Pub Date : 2024-12-27DOI: 10.1016/j.cattod.2024.115179
Rachelle M. Choueiri , Stephen W. Tatarchuk , Olivia G. Parker, William M. Cooper, Leanne D. Chen
The ammonia oxidation reaction (AOR) is a reaction of great interest for its potential to upcycle ammonia waste, creating fertilizer salts beneficial for the agricultural industry. Currently, AOR catalysts typically suffer either from high onset potentials or catalyst poisoning, and better catalyst materials must be found in order for AOR to be viable for large-scale fertilizer production. Experimentally, it is difficult to study the interactions of adsorbates on catalyst surfaces on an atomic level, whereas computational studies provide us with a means to study catalysts on this scale. In this study, we use density functional theory (DFT) calculations to develop linear scaling relations for ammonia oxidation using a set of ten reference metals. The scaling relations were used in a microkinetic model to predict the most active transition metal electrocatalysts for the AOR.
{"title":"Scaling relations for ammonia oxidation","authors":"Rachelle M. Choueiri , Stephen W. Tatarchuk , Olivia G. Parker, William M. Cooper, Leanne D. Chen","doi":"10.1016/j.cattod.2024.115179","DOIUrl":"10.1016/j.cattod.2024.115179","url":null,"abstract":"<div><div>The ammonia oxidation reaction (AOR) is a reaction of great interest for its potential to upcycle ammonia waste, creating fertilizer salts beneficial for the agricultural industry. Currently, AOR catalysts typically suffer either from high onset potentials or catalyst poisoning, and better catalyst materials must be found in order for AOR to be viable for large-scale fertilizer production. Experimentally, it is difficult to study the interactions of adsorbates on catalyst surfaces on an atomic level, whereas computational studies provide us with a means to study catalysts on this scale. In this study, we use density functional theory (DFT) calculations to develop linear scaling relations for ammonia oxidation using a set of ten reference metals. The scaling relations were used in a microkinetic model to predict the most active transition metal electrocatalysts for the AOR.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"448 ","pages":"Article 115179"},"PeriodicalIF":5.2,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143093943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-20DOI: 10.1016/j.cattod.2024.115167
Vanessa S.S. Favacho , Dulce M.A. Melo , Jennifer E.L. Costa , Lalyson M.L.R. Souza , Yuri K.R.O. Silva , Amanda L. Azevedo , Ângelo A.S. Oliveira , Renata M. Braga , Rodolfo L.B.A. Medeiros
LaNiO₃ perovskite catalytic precursors synthesized via the hydrothermal method can exhibit different structures and morphologies depending on the synthesis factors, such as soft templates and pH. Depending on the structures and morphologies of the catalytic precursors, their catalytic performance (field, conversion, stability, etc.) in dry reforming of methane (DRM) may change. Thus, this study aimed to synthesize LaNiO3 catalytic precursors with rod-like morphology by the hydrothermal method without and with soft templates (CTAB and citric acid), varying pH values (9 and 13), to evaluate the best catalytic precursors in DRM. The samples were characterized by energy-dispersive X-ray spectroscopy (EDXRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), N2 adsorption-desorption analysis, H2 temperature-programmed reduction (H2-TPR), and thermogravimetric analyses (TGA/DTG/DTA). After activation, the catalysts' performance was evaluated based on a stability test in DRM for 15 h at 600 °C and with 96 L h−1 g−1 GHSV (gas hourly space velocity). Thus, the results showed that the LaNiO3 catalytic precursors synthesized without soft template at pH 9 and 13 presented rod-like morphology and were chosen for DRM application. The reducibility test showed that the catalysts synthesized at pH 9 and 13 had a degree of reduction of 69.89 % and 77.18 %, respectively. The stability test showed that the catalyst synthesized at pH 13 had a greater CH4 and CO2 conversion and stability than the catalyst synthesized at pH 9, as well as the H2 and CO yield, and H2/CO ratio. Its greater stability was assigned to its nanorod-like morphology, which favored a more homogeneous Ni0 dispersion after activation stage. Furthermore, the spent catalysts showed whisker-like carbon deposition, in which the catalyst synthesized at pH 13 (90.36 wt%) had a greater amount than the catalyst synthesized at pH 9 (47.67 wt%). Its greater whisker-like carbon deposition was assigned to the lower amount of La2O2CO3 phase formed after DRM.
{"title":"Influence of pH and soft templates on the hydrothermal synthesis of rod-shaped LaNiO3 catalytic precursors applied to dry reforming of methane for hydrogen production","authors":"Vanessa S.S. Favacho , Dulce M.A. Melo , Jennifer E.L. Costa , Lalyson M.L.R. Souza , Yuri K.R.O. Silva , Amanda L. Azevedo , Ângelo A.S. Oliveira , Renata M. Braga , Rodolfo L.B.A. Medeiros","doi":"10.1016/j.cattod.2024.115167","DOIUrl":"10.1016/j.cattod.2024.115167","url":null,"abstract":"<div><div>LaNiO₃ perovskite catalytic precursors synthesized via the hydrothermal method can exhibit different structures and morphologies depending on the synthesis factors, such as soft templates and pH. Depending on the structures and morphologies of the catalytic precursors, their catalytic performance (field, conversion, stability, etc.) in dry reforming of methane (DRM) may change. Thus, this study aimed to synthesize LaNiO<sub>3</sub> catalytic precursors with rod-like morphology by the hydrothermal method without and with soft templates (CTAB and citric acid), varying pH values (9 and 13), to evaluate the best catalytic precursors in DRM. The samples were characterized by energy-dispersive X-ray spectroscopy (EDXRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), N<sub>2</sub> adsorption-desorption analysis, H<sub>2</sub> temperature-programmed reduction (H<sub>2</sub>-TPR), and thermogravimetric analyses (TGA/DTG/DTA). After activation, the catalysts' performance was evaluated based on a stability test in DRM for 15 h at 600 °C and with 96 L h<sup>−1</sup> g<sup>−1</sup> GHSV (gas hourly space velocity). Thus, the results showed that the LaNiO<sub>3</sub> catalytic precursors synthesized without soft template at pH 9 and 13 presented rod-like morphology and were chosen for DRM application. The reducibility test showed that the catalysts synthesized at pH 9 and 13 had a degree of reduction of 69.89 % and 77.18 %, respectively. The stability test showed that the catalyst synthesized at pH 13 had a greater CH<sub>4</sub> and CO<sub>2</sub> conversion and stability than the catalyst synthesized at pH 9, as well as the H<sub>2</sub> and CO yield, and H<sub>2</sub>/CO ratio. Its greater stability was assigned to its nanorod-like morphology, which favored a more homogeneous Ni<sup>0</sup> dispersion after activation stage. Furthermore, the spent catalysts showed whisker-like carbon deposition, in which the catalyst synthesized at pH 13 (90.36 wt%) had a greater amount than the catalyst synthesized at pH 9 (47.67 wt%). Its greater whisker-like carbon deposition was assigned to the lower amount of La<sub>2</sub>O<sub>2</sub>CO<sub>3</sub> phase formed after DRM.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"448 ","pages":"Article 115167"},"PeriodicalIF":5.2,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143150020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-20DOI: 10.1016/j.cattod.2024.115171
Wiktoria Adamowicz , Marcin Kobielusz , Paweł Mikrut , Wojciech Macyk
This work elucidates the influence of exposed facets of anatase-TiO2 crystals on the efficiency and selectivity of reduction of functionalised nitrobenzene derivatives. Titanium dioxide crystals in the form of bipyramids, sheets, and belts offering different exposed facets {001}/{101}, {001}, and {100}, respectively, were synthesised. Electrochemical analysis revealed a slight positive shift in the reduction potential of belt TiO2. The highest photocurrents were observed for sheets, whereas in the presence of methanol, the photocurrent doubling effect was observed for belts and bipyramids, with the most efficient methanol oxidation in the case of belts. The highest reaction rate constant for the reduction of 3-nitrophenol and 1-iodo-4-nitrobenzene was also noticed for belts. The observed differences in the resulting photocatalytic activity of nitroaromatics reduction were attributed to different efficiencies of methanol oxidation taking place at the tested photocatalysts.
{"title":"Photocatalytic reduction of nitroaromatic compounds over tailored anatase TiO2 crystals","authors":"Wiktoria Adamowicz , Marcin Kobielusz , Paweł Mikrut , Wojciech Macyk","doi":"10.1016/j.cattod.2024.115171","DOIUrl":"10.1016/j.cattod.2024.115171","url":null,"abstract":"<div><div>This work elucidates the influence of exposed facets of anatase-TiO<sub>2</sub> crystals on the efficiency and selectivity of reduction of functionalised nitrobenzene derivatives. Titanium dioxide crystals in the form of bipyramids, sheets, and belts offering different exposed facets {001}/{101}, {001}, and {100}, respectively, were synthesised. Electrochemical analysis revealed a slight positive shift in the reduction potential of belt TiO<sub>2</sub>. The highest photocurrents were observed for sheets, whereas in the presence of methanol, the photocurrent doubling effect was observed for belts and bipyramids, with the most efficient methanol oxidation in the case of belts. The highest reaction rate constant for the reduction of 3-nitrophenol and 1-iodo-4-nitrobenzene was also noticed for belts. The observed differences in the resulting photocatalytic activity of nitroaromatics reduction were attributed to different efficiencies of methanol oxidation taking place at the tested photocatalysts.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"448 ","pages":"Article 115171"},"PeriodicalIF":5.2,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143150013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-19DOI: 10.1016/j.cattod.2024.115168
Sandra Yurani Toledo Camacho , Francisco Mediana Cabello , Sandra Contreras Iglesias , Philip R. Davies , David J. Morgan , Auttaphon Chachvalvutikul
Layered Double-Hydroxides (LDH) materials are promising catalysts for solar-driven reactions thanks to their two-dimensional and the tunability of their composition. The preparation of three bimetallic NiFe-, NiCo- and ZnAl-LDH for H2 production by the photoreforming of glycerol under UV and visible irradiation has been investigated. Different modifications were studied: calcination, thermal reduction, plus Pt loading and TiO2 doping. Samples exhibited typical features of LDHs in XRD and hexagonal crystallites and the presence of some satellite bands were observed by HAADF-STEM and XPS, respectively, though only thermal treatments modified partially or completely the LDH structure. NiCo- and ZnAl-LDH have the weakest and the most stable LDH structures, respectively. Finally, on the unmodified NiFe- and NiCo-, and ZnAl-LDH materials, photoactivity showed zero activity toward H2 production, most likely due to their narrow and wide band gap (BG), respectively, but further thermal modifications, plus the incorporation of co-catalysts such as Pt and TiO2, promoted photocatalytic activity. On the LDH containing TiO2, the modifications had variable effect, for instance, Pt photodeposition significantly enhanced activity on ZnAl-LDH, but not on NiFe-LDH.
{"title":"Layered double hydroxides for H2 generation by the photoreforming of organic compounds","authors":"Sandra Yurani Toledo Camacho , Francisco Mediana Cabello , Sandra Contreras Iglesias , Philip R. Davies , David J. Morgan , Auttaphon Chachvalvutikul","doi":"10.1016/j.cattod.2024.115168","DOIUrl":"10.1016/j.cattod.2024.115168","url":null,"abstract":"<div><div>Layered Double-Hydroxides (LDH) materials are promising catalysts for solar-driven reactions thanks to their two-dimensional and the tunability of their composition. The preparation of three bimetallic NiFe-, NiCo- and ZnAl-LDH for H<sub>2</sub> production by the photoreforming of glycerol under UV and visible irradiation has been investigated. Different modifications were studied: calcination, thermal reduction, plus Pt loading and TiO<sub>2</sub> doping. Samples exhibited typical features of LDHs in XRD and hexagonal crystallites and the presence of some satellite bands were observed by HAADF-STEM and XPS, respectively, though only thermal treatments modified partially or completely the LDH structure. NiCo- and ZnAl-LDH have the weakest and the most stable LDH structures, respectively. Finally, on the unmodified NiFe- and NiCo-, and ZnAl-LDH materials, photoactivity showed zero activity toward H<sub>2</sub> production, most likely due to their narrow and wide band gap (BG), respectively, but further thermal modifications, plus the incorporation of co-catalysts such as Pt and TiO<sub>2</sub>, promoted photocatalytic activity. On the LDH containing TiO<sub>2,</sub> the modifications had variable effect, for instance, Pt photodeposition significantly enhanced activity on ZnAl-LDH, but not on NiFe-LDH.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"448 ","pages":"Article 115168"},"PeriodicalIF":5.2,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143098153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-19DOI: 10.1016/j.cattod.2024.115166
Rosembergue Gabriel Lima Gonçalves , Gabriel Liscia Catuzo , José Mansur Assaf , Elisabete Moreira Assaf
This study investigated catalysts derived from layered double hydroxides (LDH) with and without potassium in the Reverse Water Gas-Shift (RWGS) reaction. According to the results, despite the addition of potassium reducing the catalysts´ porosity and altering their morphology, K improved their efficiency by decreasing CH4 production and increasing selectivity towards CO. An evaluation of the K impregnation method demonstrated when not calcined prior to the impregnation process with 5 wt% of K (MgFe/K), the material showed better catalytic performance in comparison to catalysts calcined at 500 (MgFe500/K) and 800 °C (MgFe500/K). Adjustments in parameters such as temperature, gas flow rates, and H2:CO2 ratio offer a pathway for increasing selectivity for CO in the RWGS reaction. In situ DRIFTS analyses revealed changes in bands associated with CO32 − and *HCOO species, offering insights into CO2 activation and suggesting the involvement of formate-mediated pathways as responsible for CO production.
{"title":"Evaluation of the potassium incorporation method in MgFe catalysts derived from layered double hydroxides in the hydrogenation of CO2","authors":"Rosembergue Gabriel Lima Gonçalves , Gabriel Liscia Catuzo , José Mansur Assaf , Elisabete Moreira Assaf","doi":"10.1016/j.cattod.2024.115166","DOIUrl":"10.1016/j.cattod.2024.115166","url":null,"abstract":"<div><div>This study investigated catalysts derived from layered double hydroxides (LDH) with and without potassium in the Reverse Water Gas-Shift (RWGS) reaction. According to the results, despite the addition of potassium reducing the catalysts´ porosity and altering their morphology, K improved their efficiency by decreasing CH<sub>4</sub> production and increasing selectivity towards CO. An evaluation of the K impregnation method demonstrated when not calcined prior to the impregnation process with 5 wt% of K (MgFe/K), the material showed better catalytic performance in comparison to catalysts calcined at 500 (MgFe500/K) and 800 °C (MgFe500/K). Adjustments in parameters such as temperature, gas flow rates, and H<sub>2</sub>:CO<sub>2</sub> ratio offer a pathway for increasing selectivity for CO in the RWGS reaction. <em>In situ</em> DRIFTS analyses revealed changes in bands associated with CO<sub>3</sub><sup>2 −</sup> and *HCOO species, offering insights into CO<sub>2</sub> activation and suggesting the involvement of formate-mediated pathways as responsible for CO production.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"448 ","pages":"Article 115166"},"PeriodicalIF":5.2,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143093945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-18DOI: 10.1016/j.cattod.2024.115170
Xinli Tong, Emiel J.M. Hensen, Haichao Liu, De Chen, Matthias Beller, Biaohua Chen, Yongdan Li
{"title":"Preface: Catalysis in biomass to fuel and chemicals (The 4th international symposium on catalytic science and technology in sustainable energy and environment, EECAT2023)","authors":"Xinli Tong, Emiel J.M. Hensen, Haichao Liu, De Chen, Matthias Beller, Biaohua Chen, Yongdan Li","doi":"10.1016/j.cattod.2024.115170","DOIUrl":"10.1016/j.cattod.2024.115170","url":null,"abstract":"","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"448 ","pages":"Article 115170"},"PeriodicalIF":5.2,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143093946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Given the growing need to address emerging contaminants in water systems, particularly pharmaceutical compounds, there is a pressing demand for advanced and eco-friendly technologies capable of effectively degrading these pollutants. Heterogeneous photocatalysts, especially those based on TiO2, have shown considerable promise in water purification efforts. However, TiO2’s efficiency is primarily confined to the ultraviolet region (< 380 nm) due to its large band gap energy (3.2 eV) in the anatase phase. To overcome this limitation and extend the use of TiO2-based photocatalysts to the visible light spectrum, combining titania with other oxides that are sensitive to visible light has proven to be a successful strategy. Ceria (CeO2), with its Ce3 +/Ce4+ redox pair, enhances photocatalytic activity, while CuO is recognized for its ability to promote visible light responsiveness in TiO2 catalysts. This study explores a one-pot soft-hard templating Solution Combustion Synthesis (SCS) approach to prepare a series of CeO2-CuO-TiO2 nanostructures with different compositions, as effective heterogeneous photocatalysts for visible light-assisted degradation of organic contaminants. The performance of these photocatalysts was investigated both under UV and visible light irradiation, for methylene blue and nalidixic acid degradation, respectively, and compared to those of commercially available TiO2 nanomaterials used as references. Structural, morphological, textural, and redox analyses demonstrate that the synergistic interaction between the CeO2 and CuO phases with TiO2 significantly boosts the photocatalytic performance, particularly under visible light. Notably, the-top performing ternary photocatalyst reached a degradation rate of 62.9 % in 90 min, surpassing the reference TiO2 P25, which achieved 45 % under the same experimental conditions. The study highlights the potential of SCS as an effective synthetic method for producing nanostructured materials with controlled composition and structure. This approach promisingly addresses the environmental challenge of degrading organic contaminants in water using visible light.
{"title":"Soft-hard templating solution combustion synthesized CeO2-CuO-TiO2 nanostructures for visible light photocatalysis","authors":"Francesca Deganello , Massimo Dell’Edera , Leonarda Francesca Liotta , Roberto Comparelli , Maria Lucia Curri","doi":"10.1016/j.cattod.2024.115169","DOIUrl":"10.1016/j.cattod.2024.115169","url":null,"abstract":"<div><div>Given the growing need to address emerging contaminants in water systems, particularly pharmaceutical compounds, there is a pressing demand for advanced and eco-friendly technologies capable of effectively degrading these pollutants. Heterogeneous photocatalysts, especially those based on TiO<sub>2</sub>, have shown considerable promise in water purification efforts. However, TiO<sub>2</sub>’s efficiency is primarily confined to the ultraviolet region (< 380 nm) due to its large band gap energy (3.2 eV) in the anatase phase. To overcome this limitation and extend the use of TiO<sub>2</sub>-based photocatalysts to the visible light spectrum, combining titania with other oxides that are sensitive to visible light has proven to be a successful strategy. Ceria (CeO<sub>2</sub>), with its Ce<sup>3 +</sup>/Ce<sup>4+</sup> redox pair, enhances photocatalytic activity, while CuO is recognized for its ability to promote visible light responsiveness in TiO<sub>2</sub> catalysts. This study explores a one-pot soft-hard templating Solution Combustion Synthesis (SCS) approach to prepare a series of CeO<sub>2</sub>-CuO-TiO<sub>2</sub> nanostructures with different compositions, as effective heterogeneous photocatalysts for visible light-assisted degradation of organic contaminants. The performance of these photocatalysts was investigated both under UV and visible light irradiation, for methylene blue and nalidixic acid degradation, respectively, and compared to those of commercially available TiO<sub>2</sub> nanomaterials used as references. Structural, morphological, textural, and redox analyses demonstrate that the synergistic interaction between the CeO<sub>2</sub> and CuO phases with TiO<sub>2</sub> significantly boosts the photocatalytic performance, particularly under visible light. Notably, the-top performing ternary photocatalyst reached a degradation rate of 62.9 % in 90 min, surpassing the reference TiO<sub>2</sub> P25, which achieved 45 % under the same experimental conditions. The study highlights the potential of SCS as an effective synthetic method for producing nanostructured materials with controlled composition and structure. This approach promisingly addresses the environmental challenge of degrading organic contaminants in water using visible light.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"448 ","pages":"Article 115169"},"PeriodicalIF":5.2,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143093949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-15DOI: 10.1016/j.cattod.2024.115165
Evellyn Patricia Santos da Silva, Lucas Natã de Melo, Janaína Heberle Bortoluzzi, Simoni Margareti Plentz Meneghetti
This study investigated, for the first time, the use of a series of complexes based on Sn(IV) as catalysts in the esterification of levulinic acid (LA) with glycerol (GLY): dibutyltin dichloride (Bu2SnCl2), dimethyltin dichloride (Me2SnCl2), butyltin trichloride (BuSnCl3), methyltin trichloride (MeSnCl3), butylstanic acid (BuSnO(OH)), di-n-butyltin oxide (Bu2SnO) and dibutyltin dilaurate (Bu2SnLau2). The influences of various reaction conditions, including catalyst nature and loading, reaction time, proportion of reactants, and temperature, were investigated. The most active Sn(IV) complex (BuSnCl3; kap = 52,8 × 10−3 min−1) led to a GLY conversion of ∼ 74 % in the first 15 min and ∼ 97 % in 360 min, with a total formation of 26.5 % GML, 56.0 % GDL and 14.0 % GTL (360 min, 100 °C; molar ratio LA:GLI:CAT of 4:1:0.01). From the apparent rate constants (kap) determined at various temperatures, it was possible to estimate the activation energy (AE) for the GLY conversion, which was 12.5 kJ mol−1 in the presence of BuSnCl3 and 24 kJ mol−1 for the reaction performed without a catalyst, representing a decrease of approximately 50 % in the AE. This auspicious result associated with the comparison with reactions performed and using conventional Bronsted acid catalysts (hydrochloric acid (HCl) and p-toluenesulfonic acid (p-TsOH)) shows the potential of systems based on Sn(IV), without the drawbacks associated with the use of the aforementioned acids, such as reactor corrosion, among others.
{"title":"Synthesis of glycerol levulinates in the presence of Sn(IV) catalysts: Evaluation of the catalyst nature and reactional parameters","authors":"Evellyn Patricia Santos da Silva, Lucas Natã de Melo, Janaína Heberle Bortoluzzi, Simoni Margareti Plentz Meneghetti","doi":"10.1016/j.cattod.2024.115165","DOIUrl":"10.1016/j.cattod.2024.115165","url":null,"abstract":"<div><div>This study investigated, for the first time, the use of a series of complexes based on Sn(IV) as catalysts in the esterification of levulinic acid (LA) with glycerol (GLY): dibutyltin dichloride (Bu<sub>2</sub>SnCl<sub>2</sub>), dimethyltin dichloride (Me<sub>2</sub>SnCl<sub>2</sub>), butyltin trichloride (BuSnCl<sub>3</sub>), methyltin trichloride (MeSnCl<sub>3</sub>), butylstanic acid (BuSnO(OH)), di-n-butyltin oxide (Bu<sub>2</sub>SnO) and dibutyltin dilaurate (Bu<sub>2</sub>SnLau<sub>2</sub>). The influences of various reaction conditions, including catalyst nature and loading, reaction time, proportion of reactants, and temperature, were investigated. The most active Sn(IV) complex (BuSnCl<sub>3</sub>; k<sub>ap</sub> = 52,8 × 10<sup>−3</sup> min<sup>−1</sup>) led to a GLY conversion of ∼ 74 % in the first 15 min and ∼ 97 % in 360 min, with a total formation of 26.5 % GML, 56.0 % GDL and 14.0 % GTL (360 min, 100 °C; molar ratio LA:GLI:CAT of 4:1:0.01). From the apparent rate constants (k<sub>ap</sub>) determined at various temperatures, it was possible to estimate the activation energy (AE) for the GLY conversion, which was 12.5 kJ mol<sup>−1</sup> in the presence of BuSnCl<sub>3</sub> and 24 kJ mol<sup>−1</sup> for the reaction performed without a catalyst, representing a decrease of approximately 50 % in the AE. This auspicious result associated with the comparison with reactions performed and using conventional Bronsted acid catalysts (hydrochloric acid (HCl) and p-toluenesulfonic acid (p-TsOH)) shows the potential of systems based on Sn(IV), without the drawbacks associated with the use of the aforementioned acids, such as reactor corrosion, among others.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"448 ","pages":"Article 115165"},"PeriodicalIF":5.2,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143093947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The excess glycerol generated as a by-product in the biodiesel sector has intrigued researchers to explore the catalytic pathways for the transformation of this platform molecule to value-added components, such as glycerol carbonate. In the present investigation, Cu/In2O3/ZnO catalyst with variable Cu loading was synthesized utilizing a conventional precipitation technique. The resultant catalyst was employed for direct carbonation of glycerol using CO2 for the production of glycerol carbonate. The incorporation of Cu into the In2O3/ZnO system contributed significantly in improving the catalytic property of the material. The impact of various reaction parameters, including the presence of dehydrating agent, reaction temperature, time, and CO2 pressure on the resultant product of the reaction was systematically assessed. Under the optimized reaction conditions of 150 ºC temperature, 5 h reaction time, 5 MPa CO2 pressure, and 30 mmol of 2-cyanopyridine, the maximum yield of glycerol carbonate recorded was 24.32 %. Catalyst’s heterogeneity was confirmed using Sheldon’s hot filtration test.
{"title":"Synthesis of glycerol carbonate from glycerol and CO2 over Cu/In2O3/ZnO nanostructured catalyst","authors":"Ankita Sarkar , Tushar Tyagi , Sachin Sharma , Vedant Joshi , Prasanta Gogoi , Amrit Puzari , Bappi Paul","doi":"10.1016/j.cattod.2024.115164","DOIUrl":"10.1016/j.cattod.2024.115164","url":null,"abstract":"<div><div>The excess glycerol generated as a by-product in the biodiesel sector has intrigued researchers to explore the catalytic pathways for the transformation of this platform molecule to value-added components, such as glycerol carbonate. In the present investigation, Cu/In<sub>2</sub>O<sub>3</sub>/ZnO catalyst with variable Cu loading was synthesized utilizing a conventional precipitation technique. The resultant catalyst was employed for direct carbonation of glycerol using CO<sub>2</sub> for the production of glycerol carbonate. The incorporation of Cu into the In<sub>2</sub>O<sub>3</sub>/ZnO system contributed significantly in improving the catalytic property of the material. The impact of various reaction parameters, including the presence of dehydrating agent, reaction temperature, time, and CO<sub>2</sub> pressure on the resultant product of the reaction was systematically assessed. Under the optimized reaction conditions of 150 ºC temperature, 5 h reaction time, 5 MPa CO<sub>2</sub> pressure, and 30 mmol of 2-cyanopyridine, the maximum yield of glycerol carbonate recorded was 24.32 %. Catalyst’s heterogeneity was confirmed using Sheldon’s hot filtration test.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"448 ","pages":"Article 115164"},"PeriodicalIF":5.2,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143093944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-11DOI: 10.1016/j.cattod.2024.115162
Rudolf Ricka , Agnieszka Wanag , Ewelina Kusiak-Nejman , Miroslava Filip Edelmannová , Martin Reli , Marcin Łapinski , Grzegorz Słowik , Antoni W. Morawski , Kamila Kočí
This study investigates the synthesis and characterization of Black TiO2 photocatalyst (TiO2-x) through the sol-gel method combined with NaBH4 reduction at different temperatures (350 °C, 500 °C, and 650 °C). The photocatalytic performance for CO2 reduction was evaluated, revealing that TiO2-x_500°C sample exhibited the highest efficiency. This enhanced performance is mainly attributed to a higher concentration of oxygen vacancies and successful nitrogen doping resulting from ammonia water addition during synthesis. Comprehensive characterization techniques, including Raman spectroscopy, and XPS confirmed the presence of defects and their correlation with increased photocatalytic activity. These findings confirm the importance of defect engineering and doping in optimizing TiO2-based photocatalysts for CO2 photoreduction.
{"title":"Defective TiO2 for CO2 photoreduction: Influence of alkaline agent and reduction temperature modulation","authors":"Rudolf Ricka , Agnieszka Wanag , Ewelina Kusiak-Nejman , Miroslava Filip Edelmannová , Martin Reli , Marcin Łapinski , Grzegorz Słowik , Antoni W. Morawski , Kamila Kočí","doi":"10.1016/j.cattod.2024.115162","DOIUrl":"10.1016/j.cattod.2024.115162","url":null,"abstract":"<div><div>This study investigates the synthesis and characterization of Black TiO<sub>2</sub> photocatalyst (TiO<sub>2-x</sub>) through the sol-gel method combined with NaBH<sub>4</sub> reduction at different temperatures (350 °C, 500 °C, and 650 °C). The photocatalytic performance for CO<sub>2</sub> reduction was evaluated, revealing that TiO<sub>2-x</sub>_500°C sample exhibited the highest efficiency. This enhanced performance is mainly attributed to a higher concentration of oxygen vacancies and successful nitrogen doping resulting from ammonia water addition during synthesis. Comprehensive characterization techniques, including Raman spectroscopy, and XPS confirmed the presence of defects and their correlation with increased photocatalytic activity. These findings confirm the importance of defect engineering and doping in optimizing TiO<sub>2</sub>-based photocatalysts for CO<sub>2</sub> photoreduction.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"448 ","pages":"Article 115162"},"PeriodicalIF":5.2,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143093948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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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