Pub Date : 2025-01-08DOI: 10.1016/j.apcata.2025.120115
L.G. Tonutti, M.A. Maquirriain, C.A. Querini, M.L. Pisarello, B.O. Dalla Costa
Heterogeneous catalysts with amphiphilic properties were studied for the esterification of glycerine with fatty acids, with the aim of developing materials that are preferentially located at the interface of immiscible reactants, and thus, potentially more active than a catalyst concentrated in the bulk of one of the phases. This was tested using SBA-15 functionalized with sulfonic groups, as well as methyl or octyl groups to provide the amphiphilic character. More hydrophobic catalysts presented higher affinity for the interface and led to higher reaction rates. However, the production of secondary products was also higher and influenced by the phase that initially filled the pores.
{"title":"Sulfonic SBA-15 silica with amphiphilic properties: Effect of incorporating hydrophobic groups on the esterification of glycerine with fatty acids","authors":"L.G. Tonutti, M.A. Maquirriain, C.A. Querini, M.L. Pisarello, B.O. Dalla Costa","doi":"10.1016/j.apcata.2025.120115","DOIUrl":"10.1016/j.apcata.2025.120115","url":null,"abstract":"<div><div>Heterogeneous catalysts with amphiphilic properties were studied for the esterification of glycerine with fatty acids, with the aim of developing materials that are preferentially located at the interface of immiscible reactants, and thus, potentially more active than a catalyst concentrated in the bulk of one of the phases. This was tested using SBA-15 functionalized with sulfonic groups, as well as methyl or octyl groups to provide the amphiphilic character. More hydrophobic catalysts presented higher affinity for the interface and led to higher reaction rates. However, the production of secondary products was also higher and influenced by the phase that initially filled the pores.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"692 ","pages":"Article 120115"},"PeriodicalIF":4.7,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136827","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 : 2025-01-04DOI: 10.1016/j.apcata.2025.120100
Shuqi Wang , Zilong Wang , Caiping Ma , Riguang Zhang , Baojun Wang , Lixia Ling
The desulfurization of thiophene and heavy metals control have received widespread attention due to the environmental issues, but their interaction mechanism is unclear. In this work, the role of CaO in thiophene desulfurization and heavy metals control was investigated. The CS bond cleavage is the rate-determining step for thiophene desulfurization with the energy barrier of 218.5 kJ/mol on the CaO surface, and the loading of heavy metal clusters Mn4, Ni4, and Cu4 on the CaO(001) surface exhibit high desulfurization activity with energy barriers of 37.2, 44.2 and 112.1 kJ/mol at 973 K. Moreover, the electronic property analysis indicates that the S atom formed by thiophene desulfurization as the active center promotes heavy metals control comparing to the CaO surface. Furthermore, the mutual promotion effect between thiophene desulfurization and heavy metals control was elucidated. The present study broadens the understanding of treating thiophene and heavy metal pollutants in coal and sludge.
{"title":"Synergism in thiophene desulfurization and heavy metals control with CaO","authors":"Shuqi Wang , Zilong Wang , Caiping Ma , Riguang Zhang , Baojun Wang , Lixia Ling","doi":"10.1016/j.apcata.2025.120100","DOIUrl":"10.1016/j.apcata.2025.120100","url":null,"abstract":"<div><div>The desulfurization of thiophene and heavy metals control have received widespread attention due to the environmental issues, but their interaction mechanism is unclear. In this work, the role of CaO in thiophene desulfurization and heavy metals control was investigated. The C<img>S bond cleavage is the rate-determining step for thiophene desulfurization with the energy barrier of 218.5 kJ/mol on the CaO surface, and the loading of heavy metal clusters Mn<sub>4</sub>, Ni<sub>4</sub>, and Cu<sub>4</sub> on the CaO(001) surface exhibit high desulfurization activity with energy barriers of 37.2, 44.2 and 112.1 kJ/mol at 973 K. Moreover, the electronic property analysis indicates that the S atom formed by thiophene desulfurization as the active center promotes heavy metals control comparing to the CaO surface. Furthermore, the mutual promotion effect between thiophene desulfurization and heavy metals control was elucidated. The present study broadens the understanding of treating thiophene and heavy metal pollutants in coal and sludge.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"692 ","pages":"Article 120100"},"PeriodicalIF":4.7,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136839","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 : 2025-01-03DOI: 10.1016/j.apcata.2025.120101
Amir Shahzad, Khezina Rafiq, Muhammad Zeeshan Abid, Habib Ur Rehman Shah, Abdul Rauf, Ejaz Hussain
Hydrogen has potential to be utilized as clean and sustainable fuel to meet increasing energy demands. In current study, photocatalytic hydrogen evolution performances of CdZnS (CZS) have been improved by incorporation of Ni and Ag metals. Hydrothermal and chemical reduction approaches were utilized to synthesize Ag@Ni−CZS catalysts. The synthesized photocatalysts were characterized by XRD, SEM equipped with EDX, FT−IR, BET, UV−Visible/DRS, X-rays photoelectron spectroscopy (XPS), PL spectroscopy, and electrochemical techniques. The results suggest that Ni and Ag supported CZS catalysts have better charge separation and defects that lead to enhanced catalytic performances. Under optimized conditions, rate of H2 evolution for Ag@Ni−CZS catalyst is 14.13 mmol g−1 h−1 (with apparent quantum efficiency of 25.60 %) which is 4.8 times higher than pure CZS (2.91 mmol g−1 h−1). Enhanced photocatalytic performance exhibited by Ag@Ni−CZS is due to synergistic effect of Ag cocatalyst and Ni dopant. Ag contents provides hot electrons through SPR induction and these electrons were quenched by Ni dopant to generate hydrogen. To find optimised rate of hydrogen evolution, various parameters like pH, catalyst dose, concentration of sacrificial reagent and power intensity have been examined.
{"title":"Catalytic hydrogen evolution on CdZnS system: Dragging the synergy between Ni dopants and Ag cocatalysts†","authors":"Amir Shahzad, Khezina Rafiq, Muhammad Zeeshan Abid, Habib Ur Rehman Shah, Abdul Rauf, Ejaz Hussain","doi":"10.1016/j.apcata.2025.120101","DOIUrl":"10.1016/j.apcata.2025.120101","url":null,"abstract":"<div><div>Hydrogen has potential to be utilized as clean and sustainable fuel to meet increasing energy demands. In current study, photocatalytic hydrogen evolution performances of CdZnS (CZS) have been improved by incorporation of Ni and Ag metals. Hydrothermal and chemical reduction approaches were utilized to synthesize Ag@Ni−CZS catalysts. The synthesized photocatalysts were characterized by XRD, SEM equipped with EDX, FT−IR, BET, UV−Visible/DRS, X-rays photoelectron spectroscopy (XPS), PL spectroscopy, and electrochemical techniques. The results suggest that Ni and Ag supported CZS catalysts have better charge separation and defects that lead to enhanced catalytic performances. Under optimized conditions, rate of H<sub>2</sub> evolution for Ag@Ni−CZS catalyst is 14.13 mmol g<sup>−1</sup> h<sup>−1</sup> (with apparent quantum efficiency of 25.60 %) which is 4.8 times higher than pure CZS (2.91 mmol g<sup>−1</sup> h<sup>−1</sup>). Enhanced photocatalytic performance exhibited by Ag@Ni−CZS is due to synergistic effect of Ag cocatalyst and Ni dopant. Ag contents provides hot electrons through SPR induction and these electrons were quenched by Ni dopant to generate hydrogen. To find optimised rate of hydrogen evolution, various parameters like pH, catalyst dose, concentration of sacrificial reagent and power intensity have been examined.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"693 ","pages":"Article 120101"},"PeriodicalIF":4.7,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143099869","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 : 2025-01-03DOI: 10.1016/j.apcata.2024.120099
Chaojie Zhang , Jiahao Zhou , Jicheng Zhou
Propane dehydrogenation received more and more attention with the increase in propylene demand and the growing extraction of shale gas. However, traditional catalysts require feed dilution with hydrogen or inert gas, thereby lowering per-pass propylene productivity. We report here, a novel hybrid nanostructure catalyst (denoted as PtSn/@-ZrO2/SBA-15) for PDH with high initial propylene formation rate (15.15 mol·gPt−1·h−1) under pure propane feed, excellent propylene selectivity (> 95 %), and especially good stability even if the propane conversion closed to thermodynamic limits. During the reaction process, the tin species were effectively stabilized. XPS, H2-TPR and a series of characterizations indicated that those superior activities and appreciable long-term stability are stemmed from synergistic catalysis and strong interface electronic effect between PtSn nanoparticles and non-crystal semiconductor film (monolayer-dispersed ZrO2) in SBA-15. Our findings provide a new perspective on the preparation of redox catalysts.
{"title":"PtSn nanoparticles anchored on monolayer ZrO2 in SBA-15 for synergistic catalytic efficient propane dehydrogenation","authors":"Chaojie Zhang , Jiahao Zhou , Jicheng Zhou","doi":"10.1016/j.apcata.2024.120099","DOIUrl":"10.1016/j.apcata.2024.120099","url":null,"abstract":"<div><div>Propane dehydrogenation received more and more attention with the increase in propylene demand and the growing extraction of shale gas. However, traditional catalysts require feed dilution with hydrogen or inert gas, thereby lowering per-pass propylene productivity. We report here, a novel hybrid nanostructure catalyst (denoted as PtSn/@-ZrO<sub>2</sub>/SBA-15) for PDH with high initial propylene formation rate (15.15 mol·g<sub>Pt</sub><sup>−1</sup>·h<sup>−1</sup>) under pure propane feed, excellent propylene selectivity (> 95 %), and especially good stability even if the propane conversion closed to thermodynamic limits. During the reaction process, the tin species were effectively stabilized. XPS, H<sub>2</sub>-TPR and a series of characterizations indicated that those superior activities and appreciable long-term stability are stemmed from synergistic catalysis and strong interface electronic effect between PtSn nanoparticles and non-crystal semiconductor film (monolayer-dispersed ZrO<sub>2</sub>) in SBA-15. Our findings provide a new perspective on the preparation of redox catalysts.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"692 ","pages":"Article 120099"},"PeriodicalIF":4.7,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137616","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 : 2025-01-02DOI: 10.1016/j.apcata.2024.120095
Daniel P. Costa , Auguste Fernandes , Eduardo Falabella S.-Aguiar , Cristiana Alves , Paulo Ferreira , José C.B. Lopes , Bruno F. Machado , M. Filipa Ribeiro
The isolated impact of the textural properties of hierarchical zeolites on the one-step Fischer-Tropsch (FT) reaction selectivity was studied. Hierarchical ZSM-5 zeolites with different pore size distributions (PSD) and similar acid properties were successfully prepared evidenced by PXRD, 27Al MAS NMR, N2 physisorption, TEM, TPD NH3 and FTIV. Physical mixtures comprising the zeolites, Co/Al2O3 and Pt/Al2O3 were used for testing. The Mixtures containing Pt/Al2O3 evidenced a decrease on the olefin content of the final products. The addition of zeolite to the mixture increased the CH4 and C2–4 selectivity and a decrease in CO2 selectivity. The hierarchical zeolites increased the selectivity towards liquid products and isomers while decreasing the consecutive cracking. The highest isomer content was obtained with the physical mixture containing the hierarchical zeolite with higher mesopore average size (60 nm) and narrow PSD, suggesting a correlation between the PSD and the isomer content of the final products.
{"title":"Exploring the influence of zeolite textural properties on the production of sustainable fuels through the Fischer-Tropsch process","authors":"Daniel P. Costa , Auguste Fernandes , Eduardo Falabella S.-Aguiar , Cristiana Alves , Paulo Ferreira , José C.B. Lopes , Bruno F. Machado , M. Filipa Ribeiro","doi":"10.1016/j.apcata.2024.120095","DOIUrl":"10.1016/j.apcata.2024.120095","url":null,"abstract":"<div><div>The isolated impact of the textural properties of hierarchical zeolites on the one-step Fischer-Tropsch (FT) reaction selectivity was studied. Hierarchical ZSM-5 zeolites with different pore size distributions (PSD) and similar acid properties were successfully prepared evidenced by PXRD, <sup>27</sup>Al MAS NMR, N2 physisorption, TEM, TPD NH<sub>3</sub> and FTIV. Physical mixtures comprising the zeolites, Co/Al<sub>2</sub>O<sub>3</sub> and Pt/Al<sub>2</sub>O<sub>3</sub> were used for testing. The Mixtures containing Pt/Al<sub>2</sub>O<sub>3</sub> evidenced a decrease on the olefin content of the final products. The addition of zeolite to the mixture increased the CH<sub>4</sub> and C<sub>2–4</sub> selectivity and a decrease in CO<sub>2</sub> selectivity. The hierarchical zeolites increased the selectivity towards liquid products and isomers while decreasing the consecutive cracking. The highest isomer content was obtained with the physical mixture containing the hierarchical zeolite with higher mesopore average size (60 nm) and narrow PSD, suggesting a correlation between the PSD and the isomer content of the final products.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"692 ","pages":"Article 120095"},"PeriodicalIF":4.7,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137611","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 : 2025-01-02DOI: 10.1016/j.apcata.2024.120098
Shaozhong Li , Xu Zhao , Yanxing Li , Tan Guo , XiuFang Zhu , Yongke Hu , Gulou Shen , Mei Wu , Jinyan Xiong
CO2 hydrogenation to methanol can reduce CO2 emissions, meanwhile, the prepared methanol can be used as chemical raw material and fuel, and the catalyst Cu-ZnO/Al2O3 exhibits good activity. Nevertheless, the activity and selectivity over the Cu-ZnO/Al2O3 still need improvement for industrialization. In addition, plenty of water will be generated during CO2 hydrogenation, which causes deactivation of the catalyst due to the hydrothermal environment in the reaction. To increase the activity and hydrothermal stability, the Cu-ZnO/AlLaO catalyst was prepared by coprecipitation method in this work, which improved the adsorption of CO2 and inhibited the adsorption of methanol due to the strong surface basicity and the interface structure of Cu and supporter, and then increased the catalytic activity and methanol selectivity. More importantly, various characterization technologies for the structures and surface properties over fresh and hydrothermal treatment catalysts showed that the La2O3 added into the catalyst greatly improved the hydrothermal stability.
{"title":"CO2 hydrogenation to methanol on Cu-ZnO/AlLaO with high activity and hydrothermal stability","authors":"Shaozhong Li , Xu Zhao , Yanxing Li , Tan Guo , XiuFang Zhu , Yongke Hu , Gulou Shen , Mei Wu , Jinyan Xiong","doi":"10.1016/j.apcata.2024.120098","DOIUrl":"10.1016/j.apcata.2024.120098","url":null,"abstract":"<div><div>CO<sub>2</sub> hydrogenation to methanol can reduce CO<sub>2</sub> emissions, meanwhile, the prepared methanol can be used as chemical raw material and fuel, and the catalyst Cu-ZnO/Al<sub>2</sub>O<sub>3</sub> exhibits good activity. Nevertheless, the activity and selectivity over the Cu-ZnO/Al<sub>2</sub>O<sub>3</sub> still need improvement for industrialization. In addition, plenty of water will be generated during CO<sub>2</sub> hydrogenation, which causes deactivation of the catalyst due to the hydrothermal environment in the reaction. To increase the activity and hydrothermal stability, the Cu-ZnO/AlLaO catalyst was prepared by coprecipitation method in this work, which improved the adsorption of CO<sub>2</sub> and inhibited the adsorption of methanol due to the strong surface basicity and the interface structure of Cu and supporter, and then increased the catalytic activity and methanol selectivity. More importantly, various characterization technologies for the structures and surface properties over fresh and hydrothermal treatment catalysts showed that the La<sub>2</sub>O<sub>3</sub> added into the catalyst greatly improved the hydrothermal stability.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"692 ","pages":"Article 120098"},"PeriodicalIF":4.7,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136838","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 : 2025-01-02DOI: 10.1016/j.apcata.2024.120092
Yu-Hang Gu , Ling-Xia Yun , Tianbao Chen , Bin Zhang , Hangtian Zhang , Jie-Xin Wang
The valorization of waste polylactic acid (PLA) for the production of high value-added chemicals is a sustainable way to avoid carbon resource waste and promote circular economy. Here, we report a one-step catalytic process to highly efficient convert waste PLA into methyl lactate (MeLA) by methanolysis with dispersions of ultrasmall ZnO nanoparticles (4–5 nm) as catalysts. The PLA conversion and MeLA yield reach above 99 % and 95 % at 110 ℃ in 15 min, respectively. The catalytic activity and energy economy coefficient of the as-prepared catalyst exceed those of other reported PLA methanolysis catalysts. Furthermore, we showcase the application of this methodology to a wide range of commercial samples. More importantly, the catalyst exhibits excellent depolymerization effect on PLA in other alcohols (ethanol, ethylene glycol). This study provides a feasible strategy for upgrading end-of-life PLA into valuable chemicals and contributing to green and circular economy.
{"title":"Highly efficient valorization of waste polylactic acid for alkyl lactate production by dispersions of ultrasmall ZnO nanoparticles","authors":"Yu-Hang Gu , Ling-Xia Yun , Tianbao Chen , Bin Zhang , Hangtian Zhang , Jie-Xin Wang","doi":"10.1016/j.apcata.2024.120092","DOIUrl":"10.1016/j.apcata.2024.120092","url":null,"abstract":"<div><div>The valorization of waste polylactic acid (PLA) for the production of high value-added chemicals is a sustainable way to avoid carbon resource waste and promote circular economy. Here, we report a one-step catalytic process to highly efficient convert waste PLA into methyl lactate (MeLA) by methanolysis with dispersions of ultrasmall ZnO nanoparticles (4–5 nm) as catalysts. The PLA conversion and MeLA yield reach above 99 % and 95 % at 110 ℃ in 15 min, respectively. The catalytic activity and energy economy coefficient of the as-prepared catalyst exceed those of other reported PLA methanolysis catalysts. Furthermore, we showcase the application of this methodology to a wide range of commercial samples. More importantly, the catalyst exhibits excellent depolymerization effect on PLA in other alcohols (ethanol, ethylene glycol). This study provides a feasible strategy for upgrading end-of-life PLA into valuable chemicals and contributing to green and circular economy.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"692 ","pages":"Article 120092"},"PeriodicalIF":4.7,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137612","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 : 2025-01-01DOI: 10.1016/j.apcata.2024.120097
Lei Wang, Xinxin Lei, Weiping Zhang
The coke deposition in methane dehydroaromatization (MDA) can be significantly reduced in the presence of methanol. Nevertheless, the coking and regeneration processes still need to be further understood for industrial application of the MDA reaction. Herein, the effects of methanol on the Mo species and coke formation during the reaction-regeneration cycles of Mo-ZSM-5/ZSM-11 intergrown zeolites in the methane and methanol co-aromatization were studied by means of XRD, TG/DTG, TPO, XPS, Raman, and solid-state NMR etc. Addition of methanol reduced the integral coke formation rates and preserved more noncarbidic molybdenum species, thereby suppressing generation of aromatic-type coke and the coke on the zeolite surface. Mo-ZSM-5/ZSM-11 intergrown zeolites were reversibly regenerated under oxidative conditions at 470 °C, however, the catalyst underwent irreversible deactivation above 555 °C. During successive reaction-regeneration cycles, the dealumination of zeolites and part of active Mo species transform into inactive and non-regenerative Al2(MoO4)3 are the main reasons for deactivation.
{"title":"Insights into the coking and regeneration processes of methanol promoted methane dehydroaromatization reaction over Mo-ZSM-5/ZSM-11 intergrown zeolites","authors":"Lei Wang, Xinxin Lei, Weiping Zhang","doi":"10.1016/j.apcata.2024.120097","DOIUrl":"10.1016/j.apcata.2024.120097","url":null,"abstract":"<div><div>The coke deposition in methane dehydroaromatization (MDA) can be significantly reduced in the presence of methanol. Nevertheless, the coking and regeneration processes still need to be further understood for industrial application of the MDA reaction. Herein, the effects of methanol on the Mo species and coke formation during the reaction-regeneration cycles of Mo-ZSM-5/ZSM-11 intergrown zeolites in the methane and methanol co-aromatization were studied by means of XRD, TG/DTG, TPO, XPS, Raman, and solid-state NMR etc. Addition of methanol reduced the integral coke formation rates and preserved more noncarbidic molybdenum species, thereby suppressing generation of aromatic-type coke and the coke on the zeolite surface. Mo-ZSM-5/ZSM-11 intergrown zeolites were reversibly regenerated under oxidative conditions at 470 °C, however, the catalyst underwent irreversible deactivation above 555 °C. During successive reaction-regeneration cycles, the dealumination of zeolites and part of active Mo species transform into inactive and non-regenerative Al<sub>2</sub>(MoO<sub>4</sub>)<sub>3</sub> are the main reasons for deactivation.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"692 ","pages":"Article 120097"},"PeriodicalIF":4.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137613","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 : 2025-01-01DOI: 10.1016/j.apcata.2024.120090
Haoran Yuan , Lingyao Wang , Siyi Li , Zejie Zhu , Jia Yao , Haoran Li , Yue Li , Junjie Qu
When oxygen is used as the oxidant in Baeyer-Villiger reaction, the excessive benzaldehyde is usually added as the sacrificial promoter, and the high price of benzaldehyde inhibits the development of this method. In this work, toluene, a much more feasible reagent comparing to benzaldehyde, was reported as a new drive for Baeyer-Villiger oxidation for the first time. Through the optimization of the metallic catalysts and solvents, the lactones are obtained accompanied with good yields of valuable benzaldehyde and benzoic acid under molecular oxygen atmosphere. Fe(NO3)3·9 H2O and N-hydroxyphthalimide were used as the efficient catalysts which were compatible for the one-pot oxidation of toluene and cyclic ketones. The process analysis suggested that the benzoic peroxyacid generated from the oxidation of toluene is the dominant oxidant for the Baeyer-Villiger reaction of cyclic ketones. The intermediate analysis, 18O2 labeling experiment and oxygen-free experiment revealed the critical role of O2 and NO3- in the co-oxidation.
{"title":"Fe(NO3)3/NHPI-mediated co-oxidation of ketones and toluene for Baeyer-Villiger reaction with molecular oxygen","authors":"Haoran Yuan , Lingyao Wang , Siyi Li , Zejie Zhu , Jia Yao , Haoran Li , Yue Li , Junjie Qu","doi":"10.1016/j.apcata.2024.120090","DOIUrl":"10.1016/j.apcata.2024.120090","url":null,"abstract":"<div><div>When oxygen is used as the oxidant in Baeyer-Villiger reaction, the excessive benzaldehyde is usually added as the sacrificial promoter, and the high price of benzaldehyde inhibits the development of this method. In this work, toluene, a much more feasible reagent comparing to benzaldehyde, was reported as a new drive for Baeyer-Villiger oxidation for the first time. Through the optimization of the metallic catalysts and solvents, the lactones are obtained accompanied with good yields of valuable benzaldehyde and benzoic acid under molecular oxygen atmosphere. Fe(NO<sub>3</sub>)<sub>3</sub>·9 H<sub>2</sub>O and <em>N</em>-hydroxyphthalimide were used as the efficient catalysts which were compatible for the one-pot oxidation of toluene and cyclic ketones. The process analysis suggested that the benzoic peroxyacid generated from the oxidation of toluene is the dominant oxidant for the Baeyer-Villiger reaction of cyclic ketones. The intermediate analysis, <sup>18</sup>O<sub>2</sub> labeling experiment and oxygen-free experiment revealed the critical role of O<sub>2</sub> and NO<sub>3</sub><sup>-</sup> in the co-oxidation.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"692 ","pages":"Article 120090"},"PeriodicalIF":4.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137615","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 : 2024-12-31DOI: 10.1016/j.apcata.2024.120096
Gwang-Jin Na , Jongha Hwang , Hongjun Park , Ryong Ryoo
In heterogeneous catalysis, the performance of supported metal catalysts is often limited by metal agglomeration. Herein, we tackle this challenge by loading Pt and Ni nanoparticles into the micropores of MFI zeolites possessing single-point defects created by ammonia/ammonium (NH3/NH4+) solution treatment. Characterization through infrared spectroscopy revealed the formation of silanol-nest defects, analogous to those produced by strong acid treatment in metallosilicate zeolites. Metal loading was performed by incipient wetness impregnation, both with and without silanol nests. The extent of silanol nests led to significant differences in Pt and Ni dispersion, as evidenced by hydrogen chemisorption and scanning transmission electron microscopy. Notably, the silanol nests enhanced catalytic activity of encapsulated Ni nanoparticles in toluene hydrogenation by 810-fold.
{"title":"Enhanced dispersion of Pt and Ni nanoparticles on ammonia-treated siliceous MFI zeolites for toluene hydrogenation","authors":"Gwang-Jin Na , Jongha Hwang , Hongjun Park , Ryong Ryoo","doi":"10.1016/j.apcata.2024.120096","DOIUrl":"10.1016/j.apcata.2024.120096","url":null,"abstract":"<div><div>In heterogeneous catalysis, the performance of supported metal catalysts is often limited by metal agglomeration. Herein, we tackle this challenge by loading Pt and Ni nanoparticles into the micropores of MFI zeolites possessing single-point defects created by ammonia/ammonium (NH<sub>3</sub>/NH<sub>4</sub><sup>+</sup>) solution treatment. Characterization through infrared spectroscopy revealed the formation of silanol-nest defects, analogous to those produced by strong acid treatment in metallosilicate zeolites. Metal loading was performed by incipient wetness impregnation, both with and without silanol nests. The extent of silanol nests led to significant differences in Pt and Ni dispersion, as evidenced by hydrogen chemisorption and scanning transmission electron microscopy. Notably, the silanol nests enhanced catalytic activity of encapsulated Ni nanoparticles in toluene hydrogenation by 810-fold.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"692 ","pages":"Article 120096"},"PeriodicalIF":4.7,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137320","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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