Journal of Catalysis最新文献_第5页

Synergistic electronic modulation of active sites in CsCuCl3 via Zn doping for photocatalytic oxidation of toluene to benzaldehyde

IF 6.5 1区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Catalysis

Pub Date : 2025-04-01 DOI: 10.1016/j.jcat.2025.116104

Yi Lu , Ahmed Mahmoud Idris , Ping Lu , Xinyan Jiang , Jin Wang , Hao Zheng , Xiandan Liang , Sheng Li , Zhengquan Li

Photocatalytic selective oxidation represents a sustainable approach for valuable chemical transformations, yet achieving high yield and selectivity of products remains a significant challenge. In this work, we demonstrate that electronic structure modulation of CsCuCl₃ halide perovskites enables highly selective photocatalytic oxidation of toluene to benzaldehyde (BD). By strategically doping Zn into CsCuCl₃, we achieved control over the electronic modulation of catalytic sites, leading to a remarkable BD yield of 4.08 mmol g⁻¹ h⁻¹ with 85.4 % selectivity under visible light irradiation. Mechanistic investigations revealed that Zn doping creates an optimal electronic structure, which simultaneously facilitates O₂ activation to form superoxide radicals and promotes selective C–H bond activation of toluene. Density functional theory calculations showed that Zn doping induces charge redistribution at Cu and Cl sites, optimizing surface energetics for both O₂ and toluene adsorption while lowering kinetic barriers for the rate-determining steps. The enhanced charge carrier separation efficiency, confirmed by spectroscopic and electrochemical analyses, further contributes to the superior catalytic performance. This work establishes electronic structure engineering as a powerful strategy for developing high-performance single-component photocatalysts and provides new insights into the selective photocatalytic oxidation reactions.

{"title":"Synergistic electronic modulation of active sites in CsCuCl3 via Zn doping for photocatalytic oxidation of toluene to benzaldehyde","authors":"Yi Lu , Ahmed Mahmoud Idris , Ping Lu , Xinyan Jiang , Jin Wang , Hao Zheng , Xiandan Liang , Sheng Li , Zhengquan Li","doi":"10.1016/j.jcat.2025.116104","DOIUrl":"10.1016/j.jcat.2025.116104","url":null,"abstract":"<div><div>Photocatalytic selective oxidation represents a sustainable approach for valuable chemical transformations, yet achieving high yield and selectivity of products remains a significant challenge. In this work, we demonstrate that electronic structure modulation of CsCuCl<sub>3</sub> halide perovskites enables highly selective photocatalytic oxidation of toluene to benzaldehyde (BD). By strategically doping Zn into CsCuCl<sub>3</sub>, we achieved control over the electronic modulation of catalytic sites, leading to a remarkable BD yield of 4.08 mmol g<sup>−1</sup> h<sup>−1</sup> with 85.4 % selectivity under visible light irradiation. Mechanistic investigations revealed that Zn doping creates an optimal electronic structure, which simultaneously facilitates O<sub>2</sub> activation to form superoxide radicals and promotes selective C–H bond activation of toluene. Density functional theory calculations showed that Zn doping induces charge redistribution at Cu and Cl sites, optimizing surface energetics for both O<sub>2</sub> and toluene adsorption while lowering kinetic barriers for the rate-determining steps. The enhanced charge carrier separation efficiency, confirmed by spectroscopic and electrochemical analyses, further contributes to the superior catalytic performance. This work establishes electronic structure engineering as a powerful strategy for developing high-performance single-component photocatalysts and provides new insights into the selective photocatalytic oxidation reactions.</div></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"447 ","pages":"Article 116104"},"PeriodicalIF":6.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143758674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

KMC study on the promotion of the water–gas shift reaction by CO-induced clustering on Cu(111)

IF 6.5 1区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Catalysis

Pub Date : 2025-03-31 DOI: 10.1016/j.jcat.2025.116115

Zi-Qiao Xue, Gui-Chang Wang

The Water–Gas Shift Reaction (WGSR) is a critical process for hydrogen production and purification. However, typically employed low-index metal surface models have limitations in capturing the catalytic active sites under actual reaction conditions. Inspired by the recently surface science studies that CO can induce the formation of copper clusters on the Cu(111) surface, we investigated the dynamic process of copper cluster formation induced by CO on the Cu(111) surface and its impact on the WGSR by employing Density Functional Theory (DFT) combined with kinetic Monte Carlo (kMC) simulation. The kMC results indicated that ejection barriers that detachment of a copper atom from the step edges of adjacent terraces, defect density on Cu(111), and CO adsorption free energy significantly influence cluster formation and morphology, with lower ejection barrier and higher defect density as well as more negative of CO adsorption free energy favors the formation of high-density small copper cluster like Cu₇ or smaller observed by experiment. Models for Cu₃ and Cu₇ clusters were established to assess their effect on WGSR by mean-field microkinetic simulation modeling (MF-MKM) as well as kMC. Our results revealed that the adsorption energy on the clusters is higher than on the Cu(111) surface, due to the decrease in the coordination number of copper atoms. The activation energy for water dissociation on the clusters is lower than on Cu(111). Microkinetic analysis indicated that the activity order for WGSR is Cu₇/Cu(111) > Cu₃/Cu(111) > Cu(111), and the reliability of the MF-MKM method was confirmed by comparing the WGSR rates with those predicted by kMC. The activity order is attributed to the reduced activation energy for water dissociation and the ability of the clusters to recombine H₂ on the terrace. This work elucidates the rules of cluster formation induced by CO and its potential impact on the reactivity of the WGSR.

{"title":"KMC study on the promotion of the water–gas shift reaction by CO-induced clustering on Cu(111)","authors":"Zi-Qiao Xue, Gui-Chang Wang","doi":"10.1016/j.jcat.2025.116115","DOIUrl":"10.1016/j.jcat.2025.116115","url":null,"abstract":"<div><div>The Water–Gas Shift Reaction (WGSR) is a critical process for hydrogen production and purification. However, typically employed low-index metal surface models have limitations in capturing the catalytic active sites under actual reaction conditions. Inspired by the recently surface science studies that CO can induce the formation of copper clusters on the Cu(111) surface, we investigatedthe dynamic process of copper cluster formation induced by CO on the Cu(111) surface and its impact on the WGSR by employing Density Functional Theory (DFT) combined with kinetic Monte Carlo (kMC) simulation. The kMC results indicated that ejection barriers that detachment of a copper atom from the step edges of adjacent terraces, defect density on Cu(111), and CO adsorption free energy significantly influence cluster formation and morphology, <em>with lower ejection barrier and higher defect density as well as more negative of CO adsorption free energy favors the formation of high-density small copper cluster like Cu<sub>7</sub> or smaller observed by experiment.</em> Models for Cu<sub>3</sub> and Cu<sub>7</sub> clusters were established to assess their effect on WGSR by mean-field microkinetic simulation modeling (MF-MKM) as well as kMC. Our results revealed that the adsorption energy on the clusters is higher than on the Cu(111) surface, due to the decrease in the coordination number of copper atoms. The activation energy for water dissociation on the clusters is lower than on Cu(111). Microkinetic analysis indicated that the a<em>ctivity order for WGSR is Cu<sub>7</sub>/Cu(111) > Cu<sub>3</sub>/Cu(111) > Cu(111</em>), and the reliability of the MF-MKM method was confirmed by comparing the WGSR rates with those predicted by kMC. The activity order is attributed to the reduced activation energy for water dissociation and the ability of the clusters to recombine H<sub>2</sub> on the terrace. This work elucidates the rules of cluster formation induced by CO and its potential impact on the reactivity of the WGSR.</div></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"447 ","pages":"Article 116115"},"PeriodicalIF":6.5,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143745254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enabling an efficient light initiated one-pot synthesis of benzimidazoles over multifunctional 2D Pt/Ni-Fe-MOF nanosheets

IF 6.5 1区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Catalysis

Pub Date : 2025-03-31 DOI: 10.1016/j.jcat.2025.116119

Hurunqing Liu, Siyang Wu, Zhaohui Li

Pt/Ni-Fe-MOF nanosheets (NSs), with small sized Pt nanoparticles of ca. 2 nm deposited on 2D Ni-Fe-MOF NSs of ca. 5.5 nm, were successfully fabricated and was used as a multifunctional catalyst for one-pot reaction between o-phenylenediamines and alcohols to produce benzimidazoles under visible light. By modulation on the reaction medium and the composition of the catalyst to regulate the individual reaction step involved, an optimum activity was achieved over 4 wt% Pt/Ni-Fe-MOF NSs in a mixed solvent of benzyl alcohol/toluene (v/v, 2/1), which showed a superior yield of 92.0 % to 2-phenylbenzimidazole. In comparison with its bulk counterpart, the superior activity observed over 2D Pt/Ni-Fe-MOF NSs can be attributed to a reduced recombination of the photogenerated charge carriers due to their short transportation path. This study first demonstrated that in addition to the different catalytic sites required, the individual reaction step involved in a one-pot tandem/cascade reaction can be regulated to enable an efficient whole reaction. Such a regulation of the rate of the individual reaction step can, to a certain degree, be achieved by modulation on the reaction medium and the component of the multifunctional catalyst. This study also provides the great potential of using 2D MOF for the construction of multifunctional catalysts for light initiated one-pot tandem/cascade reaction.

{"title":"Enabling an efficient light initiated one-pot synthesis of benzimidazoles over multifunctional 2D Pt/Ni-Fe-MOF nanosheets","authors":"Hurunqing Liu, Siyang Wu, Zhaohui Li","doi":"10.1016/j.jcat.2025.116119","DOIUrl":"10.1016/j.jcat.2025.116119","url":null,"abstract":"<div><div>Pt/Ni-Fe-MOF nanosheets (NSs), with small sized Pt nanoparticles of <em>ca.</em> 2 nm deposited on 2D Ni-Fe-MOF NSs of <em>ca</em>. 5.5 nm, were successfully fabricated and was used as a multifunctional catalyst for one-pot reaction between o-phenylenediamines and alcohols to produce benzimidazoles under visible light. By modulation on the reaction medium and the composition of the catalyst to regulate the individual reaction step involved, an optimum activity was achieved over 4 wt% Pt/Ni-Fe-MOF NSs in a mixed solvent of benzyl alcohol/toluene (v/v, 2/1), which showed a superior yield of 92.0 % to 2-phenylbenzimidazole. In comparison with its bulk counterpart, the superior activity observed over 2D Pt/Ni-Fe-MOF NSs can be attributed to a reduced recombination of the photogenerated charge carriers due to their short transportation path. This study first demonstrated that in addition to the different catalytic sites required, the individual reaction step involved in a one-pot tandem/cascade reaction can be regulated to enable an efficient whole reaction. Such a regulation of the rate of the individual reaction step can, to a certain degree, be achieved by modulation on the reaction medium and the component of the multifunctional catalyst. This study also provides the great potential of using 2D MOF for the construction of multifunctional catalysts for light initiated one-pot tandem/cascade reaction.</div></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"447 ","pages":"Article 116119"},"PeriodicalIF":6.5,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143745252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of water vapor on the reactivity of aluminosilicates in vapor-phase propanal aldol condensation

IF 6.5 1区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Catalysis

Pub Date : 2025-03-28 DOI: 10.1016/j.jcat.2025.116110

Laura Ivette Paz Herrera , Randy Cortright , J. Will Medlin

Aluminosilicate materials have been extensively studied as efficient aldol catalysts for C–C coupling reactions due to their acidic nature, high surface area, thermal stability, and porous structure. This work investigated the impact of water vapor pressure on the catalytic reactivity of aluminosilicates for the aldol condensation of propanal to 2-methyl-2-pentenal (MP). The catalytic performance of amorphous SiO₂-Al₂O₃ (A-Si-Al) and aluminated MCM-41 (Al-MCM-41) for the vapor-phase aldol condensation of propanal was evaluated at 200 °C as a function of vapor-phase water content at atmospheric pressure. Our findings demonstrate that co-feeding low water vapor pressures (1–18 kPa) with propanal enhances the rates of MP production at 200 °C on A-Si-Al. Conversely, water vapor pressures of 25 kPa result in a decrease in aldol dimer formation rates. The rate of MP production evaluated on Al-MCM-41 also increased in the presence of 5 kPa water compared to anhydrous conditions. Propylamine temperature-programmed desorption analyses revealed an increase in Brønsted acid site density when both catalysts were exposed to water, which likely accounts for the observed enhancement in aldol condensation reactivity under hydrous conditions. Reversibility testing of the water vapor effect under reaction conditions, combined with X-ray diffraction analysis of fresh, spent, and regenerated catalysts, revealed no structural changes in either aluminosilicate upon exposure to water or reaction conditions. The rates of aldol condensation and the impact of water vapor were highly consistent across both materials, suggesting that zeolite crystallinity has minimal influence on the catalytic performance.

{"title":"Effects of water vapor on the reactivity of aluminosilicates in vapor-phase propanal aldol condensation","authors":"Laura Ivette Paz Herrera , Randy Cortright , J. Will Medlin","doi":"10.1016/j.jcat.2025.116110","DOIUrl":"10.1016/j.jcat.2025.116110","url":null,"abstract":"<div><div>Aluminosilicate materials have been extensively studied as efficient aldol catalysts for C–C coupling reactions due to their acidic nature, high surface area, thermal stability, and porous structure. This work investigated the impact of water vapor pressure on the catalytic reactivity of aluminosilicates for the aldol condensation of propanal to 2-methyl-2-pentenal (MP). The catalytic performance of amorphous SiO<sub>2</sub>-Al<sub>2</sub>O<sub>3</sub> (A-Si-Al) and aluminated MCM-41 (Al-MCM-41) for the vapor-phase aldol condensation of propanal was evaluated at 200 °C as a function of vapor-phase water content at atmospheric pressure. Our findings demonstrate that co-feeding low water vapor pressures (1–18 kPa) with propanal enhances the rates of MP production at 200 °C on A-Si-Al. Conversely, water vapor pressures of 25 kPa result in a decrease in aldol dimer formation rates. The rate of MP production evaluated on Al-MCM-41 also increased in the presence of 5 kPa water compared to anhydrous conditions. Propylamine temperature-programmed desorption analyses revealed an increase in Brønsted acid site density when both catalysts were exposed to water, which likely accounts for the observed enhancement in aldol condensation reactivity under hydrous conditions. Reversibility testing of the water vapor effect under reaction conditions, combined with X-ray diffraction analysis of fresh, spent, and regenerated catalysts, revealed no structural changes in either aluminosilicate upon exposure to water or reaction conditions. The rates of aldol condensation and the impact of water vapor were highly consistent across both materials, suggesting that zeolite crystallinity has minimal influence on the catalytic performance.</div></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"447 ","pages":"Article 116110"},"PeriodicalIF":6.5,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143734399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Surface hydroxyl on TiO2 promoted formation of α-C radical and oxaziridine intermediates in aerobic oxidation of amine into oxime

IF 6.5 1区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Catalysis

Pub Date : 2025-03-28 DOI: 10.1016/j.jcat.2025.116111

Huacheng Ying , Zeyu Wen , Jia Yao , Mowei Zhou , Yongtao Wang , Haoran Li

Constructing N−O bond in amines via aerobic oxidation is of high interest for producing cyclohexanone oxime; however, the mechanism remains disputed. Concerning TiO₂/NHPI co-catalyzed aerobic oxidation of cyclohexylamine, here a convincing mechanism involving α-C radical and oxaziridine as key intermediates is demonstrated. All the evidences from electron paramagnetic resonance, mass spectrometry, and product analysis with methylated substrates lead to the same story about the mechanism, where both radical translocation of cyclohexylamino radical and epoxidation of 1-hydroperoxycyclohexylamine are mediated by double proton transfer and are the key to convert amine into oxime. Near IR analysis indicate that surface hydroxyl groups on TiO₂ facilitate the double proton transfer process. Here the unveiled role of surface hydroxyl on TiO₂ highlights its potential for broader applications in amine activation. Additionally, the well-established radical mechanism provides valuable insight into the construction of N−O bonds in amines.

{"title":"Surface hydroxyl on TiO2 promoted formation of α-C radical and oxaziridine intermediates in aerobic oxidation of amine into oxime","authors":"Huacheng Ying , Zeyu Wen , Jia Yao , Mowei Zhou , Yongtao Wang , Haoran Li","doi":"10.1016/j.jcat.2025.116111","DOIUrl":"10.1016/j.jcat.2025.116111","url":null,"abstract":"<div><div>Constructing N−O bond in amines via aerobic oxidation is of high interest for producing cyclohexanone oxime; however, the mechanism remains disputed. Concerning TiO<sub>2</sub>/NHPI co-catalyzed aerobic oxidation of cyclohexylamine, here a convincing mechanism involving α-C radical and oxaziridine as key intermediates is demonstrated. All the evidences from electron paramagnetic resonance, mass spectrometry, and product analysis with methylated substrates lead to the same story about the mechanism, where both radical translocation of cyclohexylamino radical and epoxidation of 1-hydroperoxycyclohexylamine are mediated by double proton transfer and are the key to convert amine into oxime. Near IR analysis indicate that surface hydroxyl groups on TiO<sub>2</sub> facilitate the double proton transfer process. Here the unveiled role of surface hydroxyl on TiO<sub>2</sub> highlights its potential for broader applications in amine activation. Additionally, the well-established radical mechanism provides valuable insight into the construction of N−O bonds in amines.</div></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"447 ","pages":"Article 116111"},"PeriodicalIF":6.5,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143734400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Boosting CO2 electroreduction to ethylene via CoII-porphyrin regulated Cu2O/Cu nanocomposite

IF 6.5 1区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Catalysis

Pub Date : 2025-03-27 DOI: 10.1016/j.jcat.2025.116109

Yanyan Zhang , Lingling Peng , Xinming Li , Xiaohu Zhang , Renjie Li , Yuexing Zhang , Tianyou Peng

CO₂ electroreduction (CO₂ER) into high value-added chemicals or fuels is of great significance to solve the current energy shortage and realize the carbon cycle. Although there are reports that Cu-based CO₂ER catalysts can achieve multicarbon products, the influence of the microenvironment of Cu-based catalysts on their valence states, interface and CO₂ER performance still deserve further investigation. Herein, a Co^II-porphyrin derivative (m-CoTPyP) is used to decorate on Cu₂O/Cu nanoparticles with Cu⁺/Cu⁰ mixed valence states and Cu₂O/Cu interface for constructing a novel CoTPyP-Cu₂O/Cu composite, where m-CoTPyP as ultrathin layer on Cu₂O/Cu nanoparticles can not only efficiently promote the adsorption/activation of CO₂ and the formation of *CO on the active sites by regulating the microenvironment via H-bonding, but also improve the stability of Cu valence states. Moreover, the Cu⁺/Cu⁰ mixed valence states and abundant Cu₂O/Cu interfaces of the Cu₂O/Cu nanoparticles significantly enhance the electron transfer rate and CC coupling kinetics. Specifically, the CoTPyP-Cu₂O/Cu(1:15) delivers an ethylene (C₂H₄) Faraday efficiency up to 71 % and excellent stability (>50 h). This work provides a new perspective on the structural design of CO₂ER catalyst with synergistic active sites, high Faraday efficiency and selectivity of C₂H₄ by regulating the microenvironment.

{"title":"Boosting CO2 electroreduction to ethylene via CoII-porphyrin regulated Cu2O/Cu nanocomposite","authors":"Yanyan Zhang , Lingling Peng , Xinming Li , Xiaohu Zhang , Renjie Li , Yuexing Zhang , Tianyou Peng","doi":"10.1016/j.jcat.2025.116109","DOIUrl":"10.1016/j.jcat.2025.116109","url":null,"abstract":"<div><div>CO<sub>2</sub> electroreduction (CO<sub>2</sub>ER) into high value-added chemicals or fuels is of great significance to solve the current energy shortage and realize the carbon cycle. Although there are reports that Cu-based CO<sub>2</sub>ER catalysts can achieve multicarbon products, the influence of the microenvironment of Cu-based catalysts on their valence states, interface and CO<sub>2</sub>ER performance still deserve further investigation. Herein, a Co<sup>II</sup>-porphyrin derivative (<em>m</em>-CoTPyP) is used to decorate on Cu<sub>2</sub>O/Cu nanoparticles with Cu<sup>+</sup>/Cu<sup>0</sup> mixed valence states and Cu<sub>2</sub>O/Cu interface for constructing a novel CoTPyP-Cu<sub>2</sub>O/Cu composite, where <em>m</em>-CoTPyP as ultrathin layer on Cu<sub>2</sub>O/Cu nanoparticles can not only efficiently promote the adsorption/activation of CO<sub>2</sub> and the formation of *CO on the active sites by regulating the microenvironment <em>via</em> H-bonding, but also improve the stability of Cu valence states. Moreover, the Cu<sup>+</sup>/Cu<sup>0</sup> mixed valence states and abundant Cu<sub>2</sub>O/Cu interfaces of the Cu<sub>2</sub>O/Cu nanoparticles significantly enhance the electron transfer rate and C<img>C coupling kinetics. Specifically, the CoTPyP-Cu<sub>2</sub>O/Cu(1:15) delivers an ethylene (C<sub>2</sub>H<sub>4</sub>) Faraday efficiency up to 71 % and excellent stability (>50 h). This work provides a new perspective on the structural design of CO<sub>2</sub>ER catalyst with synergistic active sites, high Faraday efficiency and selectivity of C<sub>2</sub>H<sub>4</sub> by regulating the microenvironment.</div></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"447 ","pages":"Article 116109"},"PeriodicalIF":6.5,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Passivation of Brønsted acid sites at external surfaces of MFI zeolites and effects on propene oligomerization catalysis

IF 6.5 1区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Catalysis

Pub Date : 2025-03-27 DOI: 10.1016/j.jcat.2025.116107

Ricem Diaz Arroyo, Rajamani Gounder

Alkene oligomerization to higher molecular weight products is a useful route for converting light hydrocarbon gases to liquid transportation fuels. Heterogeneous distributions of Brønsted acid sites in zeolites, arising from spatial gradients of Al centers in intracrystalline regions and at unconfined extracrystalline surfaces, influence rates, selectivity, and deactivation for acid-catalyzed reactions. Here, we synthesized core@shell materials composed of Al-MFI cores and Si-MFI shells of varying thickness, characterized crystallite-scale Al distributions by elemental analysis and electron microscopy, and quantified fractions of external acid sites by mesitylene benzylation rate constants. Propene oligomerization rates (503 K), interpreted using effectiveness factor formalisms, revealed the strong influence of intracrystalline diffusion limitations caused by the occlusion of heavier oligomer products within zeolitic micropores during reaction, consistent with prior reports. Transient changes in dimerization rates upon step changes in propene pressure revealed more severe diffusion limitations for Al-MFI@Si-MFI than Al-MFI materials possessing external acid sites, despite similar transient 2,3-dimethylbutane adsorption rates (298 K) on both core and core@shell materials indicating that additional diffusion resistances were not introduced inherently into core@shell materials via siliceous shell growth. Rather, passivation of external acid sites allows in situ formation of recalcitrant surface carbonaceous deposits during oligomerization catalysis, which caused irreversible deactivation with time-on-stream requiring regeneration under oxidative treatments. Overall, these findings provide kinetic and mechanistic insights into the role of external acid sites in zeolites to mitigate the formation of recalcitrant carbonaceous deposits during reaction, which introduce additional diffusional barriers that influence rates, product selectivity and deactivation of zeolites during alkene oligomerization.

{"title":"Passivation of Brønsted acid sites at external surfaces of MFI zeolites and effects on propene oligomerization catalysis","authors":"Ricem Diaz Arroyo, Rajamani Gounder","doi":"10.1016/j.jcat.2025.116107","DOIUrl":"10.1016/j.jcat.2025.116107","url":null,"abstract":"<div><div>Alkene oligomerization to higher molecular weight products is a useful route for converting light hydrocarbon gases to liquid transportation fuels. Heterogeneous distributions of Brønsted acid sites in zeolites, arising from spatial gradients of Al centers in intracrystalline regions and at unconfined extracrystalline surfaces, influence rates, selectivity, and deactivation for acid-catalyzed reactions. Here, we synthesized core@shell materials composed of Al-MFI cores and Si-MFI shells of varying thickness, characterized crystallite-scale Al distributions by elemental analysis and electron microscopy, and quantified fractions of external acid sites by mesitylene benzylation rate constants. Propene oligomerization rates (503 K), interpreted using effectiveness factor formalisms, revealed the strong influence of intracrystalline diffusion limitations caused by the occlusion of heavier oligomer products within zeolitic micropores during reaction, consistent with prior reports. Transient changes in dimerization rates upon step changes in propene pressure revealed more severe diffusion limitations for Al-MFI@Si-MFI than Al-MFI materials possessing external acid sites, despite similar transient 2,3-dimethylbutane adsorption rates (298 K) on both core and core@shell materials indicating that additional diffusion resistances were not introduced inherently into core@shell materials via siliceous shell growth. Rather, passivation of external acid sites allows <em>in situ</em> formation of recalcitrant surface carbonaceous deposits during oligomerization catalysis, which caused irreversible deactivation with time-on-stream requiring regeneration under oxidative treatments. Overall, these findings provide kinetic and mechanistic insights into the role of external acid sites in zeolites to mitigate the formation of recalcitrant carbonaceous deposits during reaction, which introduce additional diffusional barriers that influence rates, product selectivity and deactivation of zeolites during alkene oligomerization.</div></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"447 ","pages":"Article 116107"},"PeriodicalIF":6.5,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Engineering lytic polysaccharide monooxygenases (LPMOs) for immobilisation on carbon nanotubes

IF 6.5 1区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Catalysis

Pub Date : 2025-03-27 DOI: 10.1016/j.jcat.2025.116108

Kelsi R. Hall , Carlotta Pontremoli , Tom Z. Emrich-Mills , Fabrizio Careddu , Matteo Bonomo , Claudia Barolo , Vincent G.H. Eijsink , Silvia Bordiga , Morten Sørlie

Lytic polysaccharide monooxygenases (LPMOs) are mononuclear copper-containing enzymes that are able to oxidise C–H bonds in the glycoside linkages of polysaccharides. However, LPMOs are prone to oxidative damage, particularly in the absence of an adequate substrate. In this work, we investigated whether we could immobilise LPMOs and whether such immobilisation could enhance the stability of LPMOs while preserving the essential catalytic properties of the copper active site. Two LPMOs from different families, LsAA9A and ScAA10C, were selected and immobilised on carboxylic acid functionalised multiwalled-CNTs, using a two-step carbodiimide activation reaction. To improve the frequency of enzyme immobilisation and guide site-specific orientation, the enzymes were engineered, introducing two lysine residues on two different loops on the LPMO surface. Assessment of the oxidase and peroxidase activities of the LPMO-MWCNT bioconjugates showed that immobilisation of the engineered LPMO was much more efficient compared to the wild-type enzymes. The immobilised enzymes still showed activity on several substrates, confirming retained catalytic competence following immobilisation. Incubation of the free and immobilised LPMOs under damaging conditions indicated a protective effect of immobilisation for LsAA9A-MWCNT, indicating that, for some LPMOs, immobilisation on MWCNTs may protect against oxidative damage.

{"title":"Engineering lytic polysaccharide monooxygenases (LPMOs) for immobilisation on carbon nanotubes","authors":"Kelsi R. Hall , Carlotta Pontremoli , Tom Z. Emrich-Mills , Fabrizio Careddu , Matteo Bonomo , Claudia Barolo , Vincent G.H. Eijsink , Silvia Bordiga , Morten Sørlie","doi":"10.1016/j.jcat.2025.116108","DOIUrl":"10.1016/j.jcat.2025.116108","url":null,"abstract":"<div><div>Lytic polysaccharide monooxygenases (LPMOs) are mononuclear copper-containing enzymes that are able to oxidise C–H bonds in the glycoside linkages of polysaccharides. However, LPMOs are prone to oxidative damage, particularly in the absence of an adequate substrate. In this work, we investigated whether we could immobilise LPMOs and whether such immobilisation could enhance the stability of LPMOs while preserving the essential catalytic properties of the copper active site. Two LPMOs from different families, <em>Ls</em>AA9A and <em>Sc</em>AA10C, were selected and immobilised on carboxylic acid functionalised multiwalled-CNTs, using a two-step carbodiimide activation reaction. To improve the frequency of enzyme immobilisation and guide site-specific orientation, the enzymes were engineered, introducing two lysine residues on two different loops on the LPMO surface. Assessment of the oxidase and peroxidase activities of the LPMO-MWCNT bioconjugates showed that immobilisation of the engineered LPMO was much more efficient compared to the wild-type enzymes. The immobilised enzymes still showed activity on several substrates, confirming retained catalytic competence following immobilisation. Incubation of the free and immobilised LPMOs under damaging conditions indicated a protective effect of immobilisation for <em>Ls</em>AA9A-MWCNT, indicating that, for some LPMOs, immobilisation on MWCNTs may protect against oxidative damage.</div></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"447 ","pages":"Article 116108"},"PeriodicalIF":6.5,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Unveiling the pathways and site requirements of methanol oxidative dehydrogenation on MoO3/TiO2 catalysts: An operando-FTIR study

IF 6.5 1区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Catalysis

Pub Date : 2025-03-27 DOI: 10.1016/j.jcat.2025.116094

Gabriel Galdames , Bastián Fuentes , Daviel Gómez , Patricia Concepción , Romel Jiménez , Alejandro Karelovic

Methanol oxidative dehydrogenation was studied on sub-monolayer and crystalline MoO₃/TiO₂-supported catalysts using operando-FTIR spectroscopy. Results revealed two distinct methyl formate (MF) formation pathways, determined by the molybdenum oxide structure. Quantitative and qualitative evidence indicated that MF and dimethoxymethane (DMM) formation occur via distinct reaction intermediates. MF formation is linked to surface formate consumption, supported by the similarity between steady-state MF formation rate measured in a fixed-bed reactor and transient initial formate consumption rate determined by operando-FTIR. Apparent activation energies for HCOO* consumption (90 and 88 kJ mol⁻¹) and MF formation (83 and 51 kJ mol⁻¹) for 2.5 and 15 at. Mo nm⁻² samples, respectively, indicate that the formation pathway depends on the molybdenum oxide structure. Oligomeric, octahedral molybdenum oxide catalysts produce MF via adsorbed formate consumption, while crystalline MoO₃ catalysts enable a parallel pathway, likely involving hemiacetal intermediates. This change in reaction pathway correlates with the structural transition from oligomeric to crystalline molybdenum oxide, as characterized by XRD, in situ Raman spectroscopy, FTIR of low-temperature CO adsorption, and XPS, among other techniques. The increase of surface formate consumption is related to the enhancement of the redox properties of the catalyst, attributed to interactions of molybdenum oxide with titania support and the presence of readily reducible Mo⁶⁺ sites that influence adsorbed formaldehyde reaction pathways. The observed activity and selectivity are explained by a three-active-site mechanism: molybdenum oxide redox sites for methanol dehydrogenation, molybdenum oxide acid sites for hemiacetal and DMM formation, and molybdenum-titania interfacial sites for HCOO* and MF formation.

{"title":"Unveiling the pathways and site requirements of methanol oxidative dehydrogenation on MoO3/TiO2 catalysts: An operando-FTIR study","authors":"Gabriel Galdames , Bastián Fuentes , Daviel Gómez , Patricia Concepción , Romel Jiménez , Alejandro Karelovic","doi":"10.1016/j.jcat.2025.116094","DOIUrl":"10.1016/j.jcat.2025.116094","url":null,"abstract":"<div><div>Methanol oxidative dehydrogenation was studied on sub-monolayer and crystalline MoO<sub>3</sub>/TiO<sub>2</sub>-supported catalysts using operando-FTIR spectroscopy. Results revealed two distinct methyl formate (MF) formation pathways, determined by the molybdenum oxide structure. Quantitative and qualitative evidence indicated that MF and dimethoxymethane (DMM) formation occur via distinct reaction intermediates. MF formation is linked to surface formate consumption, supported by the similarity between steady-state MF formation rate measured in a fixed-bed reactor and transient initial formate consumption rate determined by operando-FTIR. Apparent activation energies for HCOO* consumption (90 and 88 kJ mol<sup>−1</sup>) and MF formation (83 and 51 kJ mol<sup>−1</sup>) for 2.5 and 15 at. Mo nm<sup>−2</sup> samples, respectively, indicate that the formation pathway depends on the molybdenum oxide structure. Oligomeric, octahedral molybdenum oxide catalysts produce MF via adsorbed formate consumption, while crystalline MoO<sub>3</sub> catalysts enable a parallel pathway, likely involving hemiacetal intermediates. This change in reaction pathway correlates with the structural transition from oligomeric to crystalline molybdenum oxide, as characterized by XRD, in situ Raman spectroscopy, FTIR of low-temperature CO adsorption, and XPS, among other techniques. The increase of surface formate consumption is related to the enhancement of the redox properties of the catalyst, attributed to interactions of molybdenum oxide with titania support and the presence of readily reducible Mo<sup>6+</sup> sites that influence adsorbed formaldehyde reaction pathways. The observed activity and selectivity are explained by a three-active-site mechanism: molybdenum oxide redox sites for methanol dehydrogenation, molybdenum oxide acid sites for hemiacetal and DMM formation, and molybdenum-titania interfacial sites for HCOO* and MF formation.</div></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"447 ","pages":"Article 116094"},"PeriodicalIF":6.5,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A facile strategy to prepare single-atom catalysts anchored on TiO2 with multiple oxygen vacancies for photocatalytic hydrogen evolution

IF 6.5 1区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Catalysis

Pub Date : 2025-03-27 DOI: 10.1016/j.jcat.2025.116105

Cailing Wu , Mingming Sun , Xinyang Gao , Qifei Huang , Zhaojun Min , Yanxing Zhang , Jianji Wang

Single atom catalysts (SACs) supported on metal oxide are usually prepared at high temperature, high pressure, and complex process. Herein, a new strategy is developed to prepare SACs anchored on vacancy-rich TiO₂ using Ti₂O₃ as the support precursor under mild conditions, where Ti³⁺ on Ti₂O₃ surface acts as “traps” to capture and then reduce metal ions through electron transfer without using reducing agents. This approach is universally applicable for different single metal atoms supported on diverse phases of TiO₂ (anatase, rutile, metastable and mixed counterpart). The as-obtained Pt₁/TiO₂ with controllable Pt loading and multiple oxygen vacancies (Ov) exhibits excellent activity in photocatalytic H₂ evolution. At optimal conditions, the H₂ evolution rate is up to 95,180 μmol g⁻¹ h⁻¹, which is the highest for TiO₂ supported SACs reported.

{"title":"A facile strategy to prepare single-atom catalysts anchored on TiO2 with multiple oxygen vacancies for photocatalytic hydrogen evolution","authors":"Cailing Wu , Mingming Sun , Xinyang Gao , Qifei Huang , Zhaojun Min , Yanxing Zhang , Jianji Wang","doi":"10.1016/j.jcat.2025.116105","DOIUrl":"10.1016/j.jcat.2025.116105","url":null,"abstract":"<div><div>Single atom catalysts (SACs) supported on metal oxide are usually prepared at high temperature, high pressure, and complex process. Herein, a new strategy is developed to prepare SACs anchored on vacancy-rich TiO<sub>2</sub> using Ti<sub>2</sub>O<sub>3</sub> as the support precursor under mild conditions, where Ti<sup>3+</sup> on Ti<sub>2</sub>O<sub>3</sub> surface acts as “traps” to capture and then reduce metal ions through electron transfer without using reducing agents. This approach is universally applicable for different single metal atoms supported on diverse phases of TiO<sub>2</sub> (anatase, rutile, metastable and mixed counterpart). The as-obtained Pt<sub>1</sub>/TiO<sub>2</sub> with controllable Pt loading and multiple oxygen vacancies (Ov) exhibits excellent activity in photocatalytic H<sub>2</sub> evolution. At optimal conditions, the H<sub>2</sub> evolution rate is up to 95,180 μmol g<sup>−1</sup> h<sup>−1</sup>, which is the highest for TiO<sub>2</sub> supported SACs reported.</div></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"447 ","pages":"Article 116105"},"PeriodicalIF":6.5,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0