Pub Date : 2025-03-20DOI: 10.1016/j.jcat.2025.116070
Selena Moore, Andrew Tran, Andreas Palmateer, Jose Naranjo Mendez, Dimitri Gatzios, Peter Eschbach, Joel Miscall, Lucas D. Ellis
Recent proposed approaches in the depolymerization of waste plastics employ an olefin intermediate to produce alkanes or alkenes using olefin metathesis in tandem chemistry. Here we investigated the role of the dehydrogenation catalyst on reaction rate, kinetics, and product distribution in heterogeneous tandem dehydrogenation and olefin metathesis (alkane metathesis) of three different alkane reactants, including polyethylene. We found that many properties to which alkane dehydrogenation rates were sensitive—including metal composition, nanoparticle size, and surface doping of Re species also controlled activity in Tandem D/OM. When comparing Pd, Pt, and Pt3Sn1, supported Pd in tandem with a Re2O7 olefin metathesis catalyst showed four-fold higher activity (surface area basis) compared to Pt or Pt3Sn1 catalysts on the same support, mainly due to differences in the rate of hydrogenation. Catalyst preparation resulted in metal nanoparticles partially covered by ReOx, as seen from elemental mapping. Co-location of Re2O7 and Pd correlated with increased rates of hydrogenation (i.e., an increase in the rate of alkane formation and simultaneous lowering of the rate of alkene formation), with a reaction order in catalyst study that further supported this conclusion. The Pd and Re2O7 system displayed marked improvement compared to Pt or Pt3Sn1 with Re2O7, and previous work, in the depolymerization rate of a linear polyethylene feedstock, with over 94 % reduction in polymer molecular weight in 15 h at 190 °C using less catalyst and increased reactant loadings, while keeping solvent to polymer consumption below 2.5.
{"title":"The role of the Pt-group dehydrogenation catalyst in alkane metathesis for polyolefin deconstruction","authors":"Selena Moore, Andrew Tran, Andreas Palmateer, Jose Naranjo Mendez, Dimitri Gatzios, Peter Eschbach, Joel Miscall, Lucas D. Ellis","doi":"10.1016/j.jcat.2025.116070","DOIUrl":"https://doi.org/10.1016/j.jcat.2025.116070","url":null,"abstract":"Recent proposed approaches in the depolymerization of waste plastics employ an olefin intermediate to produce alkanes or alkenes using olefin metathesis in tandem chemistry. Here we investigated the role of the dehydrogenation catalyst on reaction rate, kinetics, and product distribution in heterogeneous tandem dehydrogenation and olefin metathesis (alkane metathesis) of three different alkane reactants, including polyethylene. We found that many properties to which alkane dehydrogenation rates were sensitive—including metal composition, nanoparticle size, and surface doping of Re species also controlled activity in Tandem D/OM. When comparing Pd, Pt, and Pt<sub>3</sub>Sn<sub>1</sub>, supported Pd in tandem with a Re<sub>2</sub>O<sub>7</sub> olefin metathesis catalyst showed four-fold higher activity (surface area basis) compared to Pt or Pt<sub>3</sub>Sn<sub>1</sub> catalysts on the same support, mainly due to differences in the rate of hydrogenation. Catalyst preparation resulted in metal nanoparticles partially covered by ReOx, as seen from elemental mapping. Co-location of Re<sub>2</sub>O<sub>7</sub> and Pd correlated with increased rates of hydrogenation (i.e., an increase in the rate of alkane formation and simultaneous lowering of the rate of alkene formation), with a reaction order in catalyst study that further supported this conclusion. The Pd and Re<sub>2</sub>O<sub>7</sub> system displayed marked improvement compared to Pt or Pt<sub>3</sub>Sn<sub>1</sub> with Re<sub>2</sub>O<sub>7</sub>, and previous work, in the depolymerization rate of a linear polyethylene feedstock, with over 94 % reduction in polymer molecular weight in 15 h at 190 °C using less catalyst and increased reactant loadings, while keeping solvent to polymer consumption below 2.5.","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"3 1","pages":""},"PeriodicalIF":7.3,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666298","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}
Pub Date : 2025-03-20DOI: 10.1016/j.jcat.2025.116089
Chuang-Chuang Su, Yong-Shun Wu, Pan-Pan Chen, An-Jiu Wen, Zheng Xu, Fei Ye, Jian Cao, Li-Wen Xu
An enantioselective synthesis of silicon-stereogenic siladihydrofuran has been developed. The key for this protocol is Cu-catalyzed Si-C bond cleavage and Si-O bond formation. In addition, catalytic hydrogenation of chiral siladihydrofuran provides carbon- and silicon-stereogenic silatetrahydrofuran in good yields with high diastereoselectivity and enantioselectivity. Ring-opening reactions of silicon-stereogenic siladihydrofuran with organolithium reagents afford enantioenriched functionalized vinylsilanes.
{"title":"Enantioselective synthesis of silicon-stereogenic siladihydrofuran via copper-catalyzed Si-C bond cleavage","authors":"Chuang-Chuang Su, Yong-Shun Wu, Pan-Pan Chen, An-Jiu Wen, Zheng Xu, Fei Ye, Jian Cao, Li-Wen Xu","doi":"10.1016/j.jcat.2025.116089","DOIUrl":"https://doi.org/10.1016/j.jcat.2025.116089","url":null,"abstract":"An enantioselective synthesis of silicon-stereogenic siladihydrofuran has been developed. The key for this protocol is Cu-catalyzed Si-C bond cleavage and Si-O bond formation. In addition, catalytic hydrogenation of chiral siladihydrofuran provides carbon- and silicon-stereogenic silatetrahydrofuran in good yields with high diastereoselectivity and enantioselectivity. Ring-opening reactions of silicon-stereogenic siladihydrofuran with organolithium reagents afford enantioenriched functionalized vinylsilanes.","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"32 1","pages":""},"PeriodicalIF":7.3,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666297","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}
Imide, a key intermediate in organic synthesis, has extensive applications. The oxidative coupling of aliphatic primary amines to imines is challenging due to low reactivity. In this study, under visible light irradiation, Cu-doped WO3 photocatalysts significantly enhanced the oxidative performance of aliphatic primary amines in both aerobic and anaerobic conditions, achieving imine yields of 94 % and 80 %, respectively. This performance is substantially superior to that of undoped WO3 and is broadly applicable to both aliphatic and aromatic amines. This improvement is attributed to the Cu doping, which not only enhances the light absorption capabilities of WO3 but also introduces oxygen vacancies that increase the adsorption and activation capacity for reactant molecules, altering the material’s band structure, enhancing light responsiveness, and promoting effective carrier separation. Additionally, radical quenching experiments confirmed the roles of holes and singlet oxygen in the aerobic reactions, while under anaerobic conditions, holes (h+) and electrons (e−) dominate, leading to high conversion rates and selectivity, as well as the detection of hydrogen. These findings provide important insights for designing efficient, non-precious metal-doped photocatalysts and advance the understanding of amine oxidative coupling.
{"title":"Effective coupling of aliphatic primary amines to imines on Cu-doped WO3 photocatalyst under aerobic and anaerobic conditions","authors":"Zhizhu Yue, Yonghe Yu, Tianjun Hu, Ying Wang, Yuhong Chang, Wenwen Chen, Linjuan Pei, Jianfeng Jia","doi":"10.1016/j.jcat.2025.116091","DOIUrl":"https://doi.org/10.1016/j.jcat.2025.116091","url":null,"abstract":"Imide, a key intermediate in organic synthesis, has extensive applications. The oxidative coupling of aliphatic primary amines to imines is challenging due to low reactivity. In this study, under visible light irradiation, Cu-doped WO<sub>3</sub> photocatalysts significantly enhanced the oxidative performance of aliphatic primary amines in both aerobic and anaerobic conditions, achieving imine yields of 94 % and 80 %, respectively. This performance is substantially superior to that of undoped WO<sub>3</sub> and is broadly applicable to both aliphatic and aromatic amines. This improvement is attributed to the Cu doping, which not only enhances the light absorption capabilities of WO<sub>3</sub> but also introduces oxygen vacancies that increase the adsorption and activation capacity for reactant molecules, altering the material’s band structure, enhancing light responsiveness, and promoting effective carrier separation. Additionally, radical quenching experiments confirmed the roles of holes and singlet oxygen in the aerobic reactions, while under anaerobic conditions, holes (h<sup>+</sup>) and electrons (e<sup>−</sup>) dominate, leading to high conversion rates and selectivity, as well as the detection of hydrogen. These findings provide important insights for designing efficient, non-precious metal-doped photocatalysts and advance the understanding of amine oxidative coupling.","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"34 1","pages":""},"PeriodicalIF":7.3,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143660687","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}
Pub Date : 2025-03-19DOI: 10.1016/j.jcat.2025.116090
Xinrui Zhang, Jordy Ramos-Yataco, Shan Jiang, Qingheng Lai, Selim Alayoglu, Jeffery T. Miller, Tobin J. Marks, Justin M. Notestein
Methane dehydroaromatization (MDA) enables the catalytic conversion of methane into aromatics, mainly benzene, along with hydrogen, in a single-step process under non-oxidative conditions. In this study, we prepared a series of isomorphously substituted Fe-ZSM-5 catalysts with exclusively isolated or low-oligomerized sites up to 3.2 % Fe weight loading by adding ethylenediaminetetraacetic acid (EDTA) to the crystallization gel. These catalysts exhibit no induction/activation period and a significantly higher maximum product yield compared to Fe/ZSM-5 catalysts prepared by the incipient wetness impregnation method and containing extensively aggregated FeOx. This investigation focuses on the evolution of Fe sites during the post-synthetic treatments. Most importantly, we demonstrate the quantitative relation between Fe site isolation and catalytic activity, proving that isolated or low-oligomerized Fe species at the exchange sites formed during post-synthetic retreatment are the active sites for methane activation.
{"title":"Identification and evolution of active sites in isomorphously substituted Fe-ZSM-5 catalysts for methane dehydroaromatization (MDA)","authors":"Xinrui Zhang, Jordy Ramos-Yataco, Shan Jiang, Qingheng Lai, Selim Alayoglu, Jeffery T. Miller, Tobin J. Marks, Justin M. Notestein","doi":"10.1016/j.jcat.2025.116090","DOIUrl":"https://doi.org/10.1016/j.jcat.2025.116090","url":null,"abstract":"Methane dehydroaromatization (MDA) enables the catalytic conversion of methane into aromatics, mainly benzene, along with hydrogen, in a single-step process under non-oxidative conditions. In this study, we prepared a series of isomorphously substituted Fe-ZSM-5 catalysts with exclusively isolated or low-oligomerized sites up to 3.2 % Fe weight loading by adding ethylenediaminetetraacetic acid (EDTA) to the crystallization gel. These catalysts exhibit no induction/activation period and a significantly higher maximum product yield compared to Fe/ZSM-5 catalysts prepared by the incipient wetness impregnation method and containing extensively aggregated FeOx. This investigation focuses on the evolution of Fe sites during the post-synthetic treatments. Most importantly, we demonstrate the quantitative relation between Fe site isolation and catalytic activity, proving that isolated or low-oligomerized Fe species at the exchange sites formed during post-synthetic retreatment are the active sites for methane activation.","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"70 1","pages":""},"PeriodicalIF":7.3,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143661092","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}
Pub Date : 2025-03-18DOI: 10.1016/j.jcat.2025.116083
Jin Gu, Hao Zhang, Miao Guo, Yanming Hu
Total furfural (FAL) hydrogenation to the industrially valuable tetrahydrofurfuryl alcohol (THFOL) involves the cascade hydrogenation of the formyl and furanic groups. However, supported metal catalysts are generally confronted with low activity, especially under mild conditions. Herein, we present a highly active Pd catalyst supported on TiO2 with a Pd loading of 0.2 wt% (0.2Pd/TiO2) for the efficient one-pot conversion of FAL to THFOL. Under mild conditions (25 °C, 60 bar H2), 0.2Pd/TiO2 achieves 90 % FAL conversion and 96 % selectivity to THFOL, outperforming the conventional high-Pd-content catalysts (e.g. 5 wt%Pd/TiO2) and most reported catalysts. Detailed characterization and kinetic investigations reveal that the exceptional performance stems from the synergistic interplay between Pd single atoms and nanoclusters on the 0.2Pd/TiO2 catalyst. Furthermore, kinetic studies highlight the crucial role of H2O in promoting the desired reaction pathway. Impressively, 0.2Pd/TiO2 demonstrates excellent stability, the activity and selectivity remain nearly identical even over seven consecutive reaction cycles. Moreover, the catalyst exhibits broad applicability, effectively hydrogenating various furanic compounds to the corresponding saturated products. This study provides key insights into the rational design of highly efficient and selective catalysts for tandem hydrogenation reactions.
{"title":"Synergistic effect of single atoms and clusters on boosting activity of TiO2-supported Pd catalysts towards total furfural hydrogenation","authors":"Jin Gu, Hao Zhang, Miao Guo, Yanming Hu","doi":"10.1016/j.jcat.2025.116083","DOIUrl":"https://doi.org/10.1016/j.jcat.2025.116083","url":null,"abstract":"Total furfural (FAL) hydrogenation to the industrially valuable tetrahydrofurfuryl alcohol (THFOL) involves the cascade hydrogenation of the formyl and furanic groups. However, supported metal catalysts are generally confronted with low activity, especially under mild conditions. Herein, we present a highly active Pd catalyst supported on TiO<sub>2</sub> with a Pd loading of 0.2 wt% (0.2Pd/TiO<sub>2</sub>) for the efficient one-pot conversion of FAL to THFOL. Under mild conditions (25 °C, 60 bar H<sub>2</sub>), 0.2Pd/TiO<sub>2</sub> achieves 90 % FAL conversion and 96 % selectivity to THFOL, outperforming the conventional high-Pd-content catalysts (e.g. 5 wt%Pd/TiO<sub>2</sub>) and most reported catalysts. Detailed characterization and kinetic investigations reveal that the exceptional performance stems from the synergistic interplay between Pd single atoms and nanoclusters on the 0.2Pd/TiO<sub>2</sub> catalyst. Furthermore, kinetic studies highlight the crucial role of H<sub>2</sub>O in promoting the desired reaction pathway. Impressively, 0.2Pd/TiO<sub>2</sub> demonstrates excellent stability, the activity and selectivity remain nearly identical even over seven consecutive reaction cycles. Moreover, the catalyst exhibits broad applicability, effectively hydrogenating various furanic compounds to the corresponding saturated products. This study provides key insights into the rational design of highly efficient and selective catalysts for tandem hydrogenation reactions.","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"25 1","pages":""},"PeriodicalIF":7.3,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143654005","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}
Lack of surface charge and poor carrier separation efficiency limit the photoelectrochemical (PEC) water splitting performance. Therefore, enhancing the charge density around the surface-active sites is an important strategy to boost the PEC performance. Herein, an in-situ strategy to construct surface S vacancies (Sv) and introduce hydroxyl groups (–OH) on the SnS2 photoanode is designed, and its PEC water splitting activity has significantly improved, reaching a maximum photocurrent density of 1.44 mA·cm−2 at 1.23 VRHE, which is 8.47 times greater than in terms of pure SnS2, and the onset potential has an obvious negative shift. Complete theoretical simulations and detailed experimental tests show that the –OH groups, as strong electron donors, transfer charge to the S vacancy sites and increase the surface charge density. Effective separation and transport of the photoinduced carriers are achieved. The ability of Sv active sites to activate and stabilize H2O molecules and reaction intermediates is also effectively improved to ensure the smooth progress of the water oxidation reaction. This work offers a novel approach for the synthesis of effective photoanodes by modifying surface defect active sites with electron donor groups.
{"title":"Engineering surface defect active sites in SnS2 nanosheets with electron-donating groups for efficient photoelectrochemical water splitting","authors":"Meng Wang, Jianli Chen, Chengming Zhang, Huihui Ding, HuanHuan Wu, Xiang Li, Shuangshuang Huai, Zhi Tang, Xiaoli Zhao, Hewen Liu, Xiufang Wang","doi":"10.1016/j.jcat.2025.116087","DOIUrl":"https://doi.org/10.1016/j.jcat.2025.116087","url":null,"abstract":"Lack of surface charge and poor carrier separation efficiency limit the photoelectrochemical (PEC) water splitting performance. Therefore, enhancing the charge density around the surface-active sites is an important strategy to boost the PEC performance. Herein, an in-situ strategy to construct surface S vacancies (S<sub>v</sub>) and introduce hydroxyl groups (–OH) on the SnS<sub>2</sub> photoanode is designed, and its PEC water splitting activity has significantly improved, reaching a maximum photocurrent density of 1.44 mA·cm<sup>−2</sup> at 1.23 V<sub>RHE</sub>, which is 8.47 times greater than in terms of pure SnS<sub>2</sub>, and the onset potential has an obvious negative shift. Complete theoretical simulations and detailed experimental tests show that the –OH groups, as strong electron donors, transfer charge to the S vacancy sites and increase the surface charge density. Effective separation and transport of the photoinduced carriers are achieved. The ability of S<sub>v</sub> active sites to activate and stabilize H<sub>2</sub>O molecules and reaction intermediates is also effectively improved to ensure the smooth progress of the water oxidation reaction. This work offers a novel approach for the synthesis of effective photoanodes by modifying surface defect active sites with electron donor groups.","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"44 1","pages":""},"PeriodicalIF":7.3,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143654004","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}
Pub Date : 2025-03-17DOI: 10.1016/j.jcat.2025.116086
Xinwan Zhao, Minjun Lei, Xiaoli Ma, Youji Li, Zhiliang Jin
Covalent organic frameworks are promising polymer semiconductors for solar-driven hydrogen production. However, rapid charge recombination and low surface reaction kinetics currently limit their photocatalytic performance. A two-dimensional Schiff base TaTp-covalent organic framework loaded with CoS2 was synthesized via a one-pot solid-state thermal method in this study, and an inorganic-organic S-scheme heterojunction CoS2/TaTp-COF composite material was thereby constructed. When the CoS2 loading reached 11 wt%, an optimal photocatalytic H2 evolution rate was demonstrated by the composite, achieving an apparent quantum efficiency of 5.91 % at 500 nm. This notable improvement can be ascribed to the π-d conjugation effect occurring at the heterojunction interface. This phenomenon facilitates effective charge separation and transfer, consequently boosting the redox capabilities. Both experimental results and theoretical calculations confirmed the successful formation of the S- scheme heterojunction and elucidated the underlying charge transfer mechanism. This research not only provides new insights into COF-based photocatalytic hydrogen evolution but also offers valuable strategies for designing heterojunction catalysts.
{"title":"Improved photocatalytic hydrogen production with the π-d conjugation between amino groups in COFs and CoS2, along with the S-scheme heterojunction","authors":"Xinwan Zhao, Minjun Lei, Xiaoli Ma, Youji Li, Zhiliang Jin","doi":"10.1016/j.jcat.2025.116086","DOIUrl":"https://doi.org/10.1016/j.jcat.2025.116086","url":null,"abstract":"Covalent organic frameworks are promising polymer semiconductors for solar-driven hydrogen production. However, rapid charge recombination and low surface reaction kinetics currently limit their photocatalytic performance. A two-dimensional Schiff base TaTp-covalent organic framework loaded with CoS<sub>2</sub> was synthesized via a one-pot solid-state thermal method in this study, and an inorganic-organic S-scheme heterojunction CoS<sub>2</sub>/TaTp-COF composite material was thereby constructed. When the CoS<sub>2</sub> loading reached 11 wt%, an optimal photocatalytic H<sub>2</sub> evolution rate was demonstrated by the composite, achieving an apparent quantum efficiency of 5.91 % at 500 nm. This notable improvement can be ascribed to the π-d conjugation effect occurring at the heterojunction interface. This phenomenon facilitates effective charge separation and transfer, consequently boosting the redox capabilities. Both experimental results and theoretical calculations confirmed the successful formation of the S- scheme heterojunction and elucidated the underlying charge transfer mechanism. This research not only provides new insights into COF-based photocatalytic hydrogen evolution but also offers valuable strategies for designing heterojunction catalysts.","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"49 1","pages":""},"PeriodicalIF":7.3,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640014","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}
How to efficiently oxidize cyclohexane through C(sp3)-H bond activation has been a major challenge in industry. In this paper, a new polyoxometalate based metal–organic frameworks, named as CUST-906 is designed and synthesized with the formula of Cu(bix)2(W10O32)0.5, (bix = 1,4-Bis(imidazol-1-ylmethyl)benzene). Decatungstate as photosensitizer, CUST-906 can catalyze the oxidation reaction of cyclohexane under visible light with mild reaction conditions, the conversion rate can reach high as 33.4 %, which is far higher than that of the industrial level (less than 4 %), and the selectivity of cyclohexanol and cyclohexanone (KA oil) is greater than 99 %. CUST-906 exhibits excellent light absorption ability and photogenerated carrier separation ability under visible light, which endows CUST-906 strong catalytic oxidation capacity and good recyclability for the oxidation reaction of cyclohexane. We delve into the discussion the activation of C(sp3)-H bonds by the hydrogen atom transfer (HAT) process of decatungstate, which synergies with the central metal to achieve the photocatalytic oxidation process via ·O2− and h+. This work provides a new idea for heterogeneous catalysis of cyclohexane oxidation.
{"title":"Visible-light-mediated oxidation of saturated C(sp3)-H bonds over [W10O32]4−-POMOFs","authors":"Yanjie Lv, Dianxiang Peng, Wenxi Zhang, Jing Sun, Huiying Sun, Xin Wang, Xiao Li, Mingwei Ma, Zhongmin Su","doi":"10.1016/j.jcat.2025.116088","DOIUrl":"https://doi.org/10.1016/j.jcat.2025.116088","url":null,"abstract":"How to efficiently oxidize cyclohexane through C(sp<sup>3</sup>)-H bond activation has been a major challenge in industry. In this paper, a new polyoxometalate based metal–organic frameworks, named as <strong>CUST-906</strong> is designed and synthesized with the formula of Cu(bix)<sub>2</sub>(W<sub>10</sub>O<sub>32</sub>)<sub>0.5</sub>, (bix = 1,4-Bis(imidazol-1-ylmethyl)benzene). Decatungstate as photosensitizer, <strong>CUST-906</strong> can catalyze the oxidation reaction of cyclohexane under visible light with mild reaction conditions, the conversion rate can reach high as 33.4 %, which is far higher than that of the industrial level (less than 4 %), and the selectivity of cyclohexanol and cyclohexanone (KA oil) is greater than 99 %. <strong>CUST-906</strong> exhibits excellent light absorption ability and photogenerated carrier separation ability under visible light, which endows <strong>CUST-906</strong> strong catalytic oxidation capacity and good recyclability for the oxidation reaction of cyclohexane. We delve into the discussion the activation of C(sp<sup>3</sup>)-H bonds by the hydrogen atom transfer (HAT) process of decatungstate, which synergies with the central metal to achieve the photocatalytic oxidation process via ·O<sub>2</sub><sup>−</sup> and h<sup>+</sup>. This work provides a new idea for heterogeneous catalysis of cyclohexane oxidation.","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"24 1","pages":""},"PeriodicalIF":7.3,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640413","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}
Pub Date : 2025-03-17DOI: 10.1016/j.jcat.2025.116071
Shivangi Singh, Yingxin Feng, Ton V.W. Janssens, Henrik Grönbeck
Cu-exchanged chabazite (Cu-CHA) is a widely applied catalyst for selective catalytic reduction of nitrogen oxides in oxygen excess. The application of Cu-CHA to exhaust from H<sub>2</sub>-fueled engines depends on the behavior of this material at high partial pressures of water. We have performed flow-reactor measurements, which show that the NO<span><span style=""></span><span data-mathml='<math xmlns="http://www.w3.org/1998/Math/MathML"><msub is="true"><mrow is="true" /><mrow is="true"><mi is="true">x</mi></mrow></msub></math>' role="presentation" style="font-size: 90%; display: inline-block; position: relative;" tabindex="0"><svg aria-hidden="true" focusable="false" height="1.163ex" role="img" style="vertical-align: -0.582ex;" viewbox="0 -250.4 504.8 500.8" width="1.172ex" xmlns:xlink="http://www.w3.org/1999/xlink"><g fill="currentColor" stroke="currentColor" stroke-width="0" transform="matrix(1 0 0 -1 0 0)"><g is="true"><g is="true"></g><g is="true" transform="translate(0,-150)"><g is="true"><use transform="scale(0.707)" xlink:href="#MJMATHI-78"></use></g></g></g></g></svg><span role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML"><msub is="true"><mrow is="true"></mrow><mrow is="true"><mi is="true">x</mi></mrow></msub></math></span></span><script type="math/mml"><math><msub is="true"><mrow is="true"></mrow><mrow is="true"><mi is="true">x</mi></mrow></msub></math></script></span> conversion at 200 °C over a Cu-CHA (3.2 wt% Cu, Si/Al=6.7) catalyst decreases with increasing partial pressures of water from 2 to 25%. Simultaneously, the apparent reaction order in water decreases from <span><span style=""></span><span data-mathml='<math xmlns="http://www.w3.org/1998/Math/MathML"><mrow is="true"><mo is="true">−</mo><mn is="true">0</mn><mo is="true">.</mo><mn is="true">17</mn></mrow></math>' role="presentation" style="font-size: 90%; display: inline-block; position: relative;" tabindex="0"><svg aria-hidden="true" focusable="false" height="2.086ex" role="img" style="vertical-align: -0.351ex;" viewbox="0 -747.2 2725.2 898.2" width="6.329ex" xmlns:xlink="http://www.w3.org/1999/xlink"><g fill="currentColor" stroke="currentColor" stroke-width="0" transform="matrix(1 0 0 -1 0 0)"><g is="true"><g is="true"><use xlink:href="#MJMAIN-2212"></use></g><g is="true" transform="translate(778,0)"><use xlink:href="#MJMAIN-30"></use></g><g is="true" transform="translate(1279,0)"><use xlink:href="#MJMAIN-2E"></use></g><g is="true" transform="translate(1724,0)"><use xlink:href="#MJMAIN-31"></use><use x="500" xlink:href="#MJMAIN-37" y="0"></use></g></g></g></svg><span role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML"><mrow is="true"><mo is="true">−</mo><mn is="true">0</mn><mo is="true">.</mo><mn is="true">17</mn></mrow></math></span></span><script type="math/mml"><math><mrow is="true"><mo is="true">−</
{"title":"Inhibition of NH3-SCR over Cu-CHA at high partial pressures of water: Measurements and DFT-based kinetic modeling","authors":"Shivangi Singh, Yingxin Feng, Ton V.W. Janssens, Henrik Grönbeck","doi":"10.1016/j.jcat.2025.116071","DOIUrl":"https://doi.org/10.1016/j.jcat.2025.116071","url":null,"abstract":"Cu-exchanged chabazite (Cu-CHA) is a widely applied catalyst for selective catalytic reduction of nitrogen oxides in oxygen excess. The application of Cu-CHA to exhaust from H<sub>2</sub>-fueled engines depends on the behavior of this material at high partial pressures of water. We have performed flow-reactor measurements, which show that the NO<span><span style=\"\"></span><span data-mathml='<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub is=\"true\"><mrow is=\"true\" /><mrow is=\"true\"><mi is=\"true\">x</mi></mrow></msub></math>' role=\"presentation\" style=\"font-size: 90%; display: inline-block; position: relative;\" tabindex=\"0\"><svg aria-hidden=\"true\" focusable=\"false\" height=\"1.163ex\" role=\"img\" style=\"vertical-align: -0.582ex;\" viewbox=\"0 -250.4 504.8 500.8\" width=\"1.172ex\" xmlns:xlink=\"http://www.w3.org/1999/xlink\"><g fill=\"currentColor\" stroke=\"currentColor\" stroke-width=\"0\" transform=\"matrix(1 0 0 -1 0 0)\"><g is=\"true\"><g is=\"true\"></g><g is=\"true\" transform=\"translate(0,-150)\"><g is=\"true\"><use transform=\"scale(0.707)\" xlink:href=\"#MJMATHI-78\"></use></g></g></g></g></svg><span role=\"presentation\"><math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub is=\"true\"><mrow is=\"true\"></mrow><mrow is=\"true\"><mi is=\"true\">x</mi></mrow></msub></math></span></span><script type=\"math/mml\"><math><msub is=\"true\"><mrow is=\"true\"></mrow><mrow is=\"true\"><mi is=\"true\">x</mi></mrow></msub></math></script></span> conversion at 200 °C over a Cu-CHA (3.2 wt% Cu, Si/Al=6.7) catalyst decreases with increasing partial pressures of water from 2 to 25%. Simultaneously, the apparent reaction order in water decreases from <span><span style=\"\"></span><span data-mathml='<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow is=\"true\"><mo is=\"true\">&#x2212;</mo><mn is=\"true\">0</mn><mo is=\"true\">.</mo><mn is=\"true\">17</mn></mrow></math>' role=\"presentation\" style=\"font-size: 90%; display: inline-block; position: relative;\" tabindex=\"0\"><svg aria-hidden=\"true\" focusable=\"false\" height=\"2.086ex\" role=\"img\" style=\"vertical-align: -0.351ex;\" viewbox=\"0 -747.2 2725.2 898.2\" width=\"6.329ex\" xmlns:xlink=\"http://www.w3.org/1999/xlink\"><g fill=\"currentColor\" stroke=\"currentColor\" stroke-width=\"0\" transform=\"matrix(1 0 0 -1 0 0)\"><g is=\"true\"><g is=\"true\"><use xlink:href=\"#MJMAIN-2212\"></use></g><g is=\"true\" transform=\"translate(778,0)\"><use xlink:href=\"#MJMAIN-30\"></use></g><g is=\"true\" transform=\"translate(1279,0)\"><use xlink:href=\"#MJMAIN-2E\"></use></g><g is=\"true\" transform=\"translate(1724,0)\"><use xlink:href=\"#MJMAIN-31\"></use><use x=\"500\" xlink:href=\"#MJMAIN-37\" y=\"0\"></use></g></g></g></svg><span role=\"presentation\"><math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow is=\"true\"><mo is=\"true\">−</mo><mn is=\"true\">0</mn><mo is=\"true\">.</mo><mn is=\"true\">17</mn></mrow></math></span></span><script type=\"math/mml\"><math><mrow is=\"true\"><mo is=\"true\">−</","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"214 1","pages":""},"PeriodicalIF":7.3,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640418","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}
Metal-enzyme integrated catalysts combine the high selectivity of enzyme catalysts with the broad substrate spectrum of metal catalysts and offer tremendous possibilities for chemoenzymatic cascade processes. However, the rational design of microenvironments in nanostructures that make metals and enzymes compatible for efficient activity still remains challenging. In this report, a nanocomposite catalyst was fabricated by integrating ultrafine Pd nanoparticles (Pd NPs) and Candida antarctica lipase B (CALB) on the hydrophobic polydopamine-coated SiO2 (SP) to enhance the compatibility of enzyme-metal catalysts. In detail, Pd NPs were in situ reduced by PDA on the SP surface, and the obtained SP-loaded Pd (Pd/SP) was hydrophobically modified by octadecyltrimethoxysilane for the subsequent adsorption immobilization of CALB to prepare the integrated catalyst, CALB/mPd/SP. The hydrophobic PDA coating on SiO2 not only stabilized the loaded ultrasmall Pd nanoparticles but also facilitated the activation of the immobilized lipase, which helped to improve the cascade catalytic efficiency of CALB/mPd/SP. Afterward, CALB/mPd/SP was used in a one-pot dynamic kinetic resolution (DKR) reaction of α-phenylethylamine with high conversion (>99 %), selectivity (93.9 %), and eep (>99 %). After 25 days of storage and 5 h of sonication, CALB/mPd/SP exhibited no significant reduction in the DKR catalytic activity. This study proposed a simple and sustainable method for the preparation of enzyme-metal cascade catalysts to enhance their stability and achieve significantly increased activity through interfacial microenvironmental modulation.
{"title":"Tailoring microenvironments of metal-enzyme cascade catalysts for efficient DKR reaction of chiral amine","authors":"Mengyu Li, Wei Zhuang, Xia Meng, Wenxia Zhang, Keke Zhang, Zhenfu Wang","doi":"10.1016/j.jcat.2025.116079","DOIUrl":"https://doi.org/10.1016/j.jcat.2025.116079","url":null,"abstract":"Metal-enzyme integrated catalysts combine the high selectivity of enzyme catalysts with the broad substrate spectrum of metal catalysts and offer tremendous possibilities for chemoenzymatic cascade processes. However, the rational design of microenvironments in nanostructures that make metals and enzymes compatible for efficient activity still remains challenging. In this report, a nanocomposite catalyst was fabricated by integrating ultrafine Pd nanoparticles (Pd NPs) and <em>Candida antarctica</em> lipase B (CALB) on the hydrophobic polydopamine-coated SiO<sub>2</sub> (SP) to enhance the compatibility of enzyme-metal catalysts. In detail, Pd NPs were in situ reduced by PDA on the SP surface, and the obtained SP-loaded Pd (Pd/SP) was hydrophobically modified by octadecyltrimethoxysilane for the subsequent adsorption immobilization of CALB to prepare the integrated catalyst, CALB/mPd/SP. The hydrophobic PDA coating on SiO<sub>2</sub> not only stabilized the loaded ultrasmall Pd nanoparticles but also facilitated the activation of the immobilized lipase, which helped to improve the cascade catalytic efficiency of CALB/mPd/SP. Afterward, CALB/mPd/SP was used in a one-pot dynamic kinetic resolution (DKR) reaction of α-phenylethylamine with high conversion (>99 %), selectivity (93.9 %), and ee<sub>p</sub> (>99 %). After 25 days of storage and 5 h of sonication, CALB/mPd/SP exhibited no significant reduction in the DKR catalytic activity. This study proposed a simple and sustainable method for the preparation of enzyme-metal cascade catalysts to enhance their stability and achieve significantly increased activity through interfacial microenvironmental modulation.","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"24 1","pages":""},"PeriodicalIF":7.3,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143635655","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}
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