Pub Date : 2024-10-21DOI: 10.1016/j.mcat.2024.114613
Pushuang Xing , Cong Li , Yixin Chen, Rong-Lan Zhang
PMoV2 was encapsulated in four MOFs (MIL-101, HKUST-1, UiO-67, ZIF-8) with different cavity sizes and window sizes using a hydrothermal synthesis method. Then, a layer of mesoporous silica was coated on the surface of the MOFs to obtain four designed three-layer encapsulated catalysts 30%PMoV2@MOF@mSiO2. The physicochemical properties of the catalysts were characterized through various characterization methods, and the influence of different MOF window sizes of the four catalysts on the removal rate of four thiophene sulfides was investigated. The optimal reaction conditions were also explored for the optimal catalyst. The results indicate that under simulated fuel of 2400 ppm, 30%PMoV2@UiO-67@mSiO2 owns the highest catalytic activity. Under optimal conditions, the total removal rate of four thiophene compounds was 91.52 %, and after ten cycles, the efficiency could still reach 86.24 %. This is attributed to the sufficient cavity size of UiO-67, which provides assurance for the loading of PMoV2 and the large window size, making it possible for the smooth reaction between sulfides and PMoV2.
{"title":"Preparation of 30%PMoV2@MOF@mSiO2 (MOF = MIL-101, HKUST-1, UiO-67, ZIF-8) catalysts and their oxidative desulfurization performance","authors":"Pushuang Xing , Cong Li , Yixin Chen, Rong-Lan Zhang","doi":"10.1016/j.mcat.2024.114613","DOIUrl":"10.1016/j.mcat.2024.114613","url":null,"abstract":"<div><div>PMoV<sub>2</sub> was encapsulated in four MOFs (MIL-101, HKUST-1, UiO-67, ZIF-8) with different cavity sizes and window sizes using a hydrothermal synthesis method. Then, a layer of mesoporous silica was coated on the surface of the MOFs to obtain four designed three-layer encapsulated catalysts 30%PMoV<sub>2</sub>@MOF@mSiO<sub>2</sub>. The physicochemical properties of the catalysts were characterized through various characterization methods, and the influence of different MOF window sizes of the four catalysts on the removal rate of four thiophene sulfides was investigated. The optimal reaction conditions were also explored for the optimal catalyst. The results indicate that under simulated fuel of 2400 ppm, 30%PMoV<sub>2</sub>@UiO-67@mSiO<sub>2</sub> owns the highest catalytic activity. Under optimal conditions, the total removal rate of four thiophene compounds was 91.52 %, and after ten cycles, the efficiency could still reach 86.24 %. This is attributed to the sufficient cavity size of UiO-67, which provides assurance for the loading of PMoV<sub>2</sub> and the large window size, making it possible for the smooth reaction between sulfides and PMoV<sub>2</sub>.</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"569 ","pages":"Article 114613"},"PeriodicalIF":3.9,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554861","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}
Carbon dots (CDs) have emerged as promising materials for photocatalytic organic transformations due to their excellent photostability, tunable electronic properties, and environmental friendliness; However, the ability of CDs to selectively generate reactive oxygen species (ROS) and its integration with organic photocatalytic synthesis applications has always been a long-term challenge. In this work, we synthesized a new nitrogen and phosphorus co-doped carbon dots (N,P-CDs) with enhanced light absorption and notable efficiency in generating superoxide anion (O2•−) selectively. Leveraging the selective generation of superoxide anions, we achieved highly efficient photooxidation of boronic acids and N-phenyl tetrahydroisoquinolines, demonstrating the practical applicability of N,P-CDs as photocatalysts and represents good functional-group tolerance as well as a broad substrate scope. This study provides valuable insights into the design of carbon-based photocatalysts with controlled ROS generation, opening new avenues for environmentally benign organic transformations.
{"title":"Carbon dot-based type I photosensitizers for photocatalytic oxidation reaction of arylboric acid and N-phenyl tetrahydroisoquinoline","authors":"Zhong-Lin Guo , Kai-kai Niu , Yu-Guang Lv , Ling-Bao Xing","doi":"10.1016/j.mcat.2024.114625","DOIUrl":"10.1016/j.mcat.2024.114625","url":null,"abstract":"<div><div>Carbon dots (CDs) have emerged as promising materials for photocatalytic organic transformations due to their excellent photostability, tunable electronic properties, and environmental friendliness; However, the ability of CDs to selectively generate reactive oxygen species (ROS) and its integration with organic photocatalytic synthesis applications has always been a long-term challenge. In this work, we synthesized a new nitrogen and phosphorus co-doped carbon dots (N,P-CDs) with enhanced light absorption and notable efficiency in generating superoxide anion (O<sub>2</sub><sup>•−</sup>) selectively. Leveraging the selective generation of superoxide anions, we achieved highly efficient photooxidation of boronic acids and N-phenyl tetrahydroisoquinolines, demonstrating the practical applicability of N,P-CDs as photocatalysts and represents good functional-group tolerance as well as a broad substrate scope. This study provides valuable insights into the design of carbon-based photocatalysts with controlled ROS generation, opening new avenues for environmentally benign organic transformations.</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"569 ","pages":"Article 114625"},"PeriodicalIF":3.9,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554860","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}
A deep eutectic solvent (DES) comprising p-toluenesulfonic acid (PTSA) and polyethylene glycol 200 (PEG200) was synthesized and applied to the Baeyer-Villiger (B-V) oxidation reaction of 2-adamantanone, which exhibited good catalytic effect and cyclic stability under relatively mild conditions. It was found that the hydrogen bond of DESs not only governed their physical properties, such as viscosity and electrical conductivity, but also influenced their chemical behavior, including the catalytic effect in B-V oxidation reaction. By adjusting the composition, the hydrogen bond properties can be optimized. This study aims to elucidate the intricate relationship between composition, hydrogen bond strength, and physicochemical properties of DESs, thereby establishing a preliminary theoretical foundation for a comprehensive understanding and construction of DESs systems. This provides a novel and promising environmentally friendly approach for the B-V oxidation reaction.
合成了一种由对甲苯磺酸（PTSA）和聚乙二醇 200（PEG200）组成的深共晶溶剂（DES），并将其应用于 2-金刚烷酮的拜尔-维里格（B-V）氧化反应，在相对温和的条件下表现出良好的催化效果和循环稳定性。研究发现，DES 的氢键不仅决定其物理性质，如粘度和导电性，还影响其化学行为，包括在 B-V 氧化反应中的催化作用。通过调整成分，可以优化氢键特性。本研究旨在阐明 DESs 的组成、氢键强度和理化性质之间错综复杂的关系，从而为全面了解和构建 DESs 系统奠定初步的理论基础。这为 B-V 氧化反应提供了一种新颖且有前景的环境友好型方法。
{"title":"Efficient catalysis for the Baeyer-Villiger oxidation reaction of 2-adamantone in acidic deep eutectic solvents","authors":"Guiyi Zhao, Weiguang Wang, Kaixuan Yang, Ting Su, Zhiguo Zhu, Hongying Lü","doi":"10.1016/j.mcat.2024.114629","DOIUrl":"10.1016/j.mcat.2024.114629","url":null,"abstract":"<div><div>A deep eutectic solvent (DES) comprising p-toluenesulfonic acid (PTSA) and polyethylene glycol 200 (PEG200) was synthesized and applied to the Baeyer-Villiger (B-V) oxidation reaction of 2-adamantanone, which exhibited good catalytic effect and cyclic stability under relatively mild conditions. It was found that the hydrogen bond of DESs not only governed their physical properties, such as viscosity and electrical conductivity, but also influenced their chemical behavior, including the catalytic effect in B-V oxidation reaction. By adjusting the composition, the hydrogen bond properties can be optimized. This study aims to elucidate the intricate relationship between composition, hydrogen bond strength, and physicochemical properties of DESs, thereby establishing a preliminary theoretical foundation for a comprehensive understanding and construction of DESs systems. This provides a novel and promising environmentally friendly approach for the B-V oxidation reaction.</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"569 ","pages":"Article 114629"},"PeriodicalIF":3.9,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554859","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 : 2024-10-19DOI: 10.1016/j.mcat.2024.114621
Maosheng Yang , Yang Feng , Jungang Wang , Zhongyi Ma , Congbiao Chen , Wei Zhang , Shupeng Guo , Hongjuan Xi , Zhancheng Ma , Bo Hou
Significant strides have been undertaken to catalyze the production of ethanol from syngas, yet the challenge remains in developing catalysts that simultaneously exhibit high activity and selectivity. In this study, we designed a high-performance Rh-Mn catalyst. The CO conversion of finally screened 1Rh1Mn/TiO2 catalyst is 51.8 %, and the total alcohol selectivity and ethanol yield are 72.1 % and 24.1 % respectively. This is the highest ethanol yield reported to date for Rh-based catalysts. Additionally, this catalyst also kept good stability. The outstanding performance is attributed to the fact that Mn facilitates the formation of Rh+ active sites, the process of CO insertion, and the generation of CH3CHO and CH3CO species—critical intermediates in ethanol production. In contrast, the unpromoted 1Rh/TiO2 catalyst showed poor ethanol selectivity and mainly produced the Rh0 species, whereas the 1Rh1Mn/TiO2 catalyst with the addition of Mn showed an increase in total alcohol and ethanol selectivity of 26.5 % and 31.3 %, respectively, as well as a reduction in CO2 of 50.4 %. In addition, we elucidated the CO2 generation and conversion pathways in the syngas to ethanol process, which is important for the effective utilization of carbon resources.
{"title":"Upgrading the performance of syngas to ethanol via Mn modified Rh-based catalyst","authors":"Maosheng Yang , Yang Feng , Jungang Wang , Zhongyi Ma , Congbiao Chen , Wei Zhang , Shupeng Guo , Hongjuan Xi , Zhancheng Ma , Bo Hou","doi":"10.1016/j.mcat.2024.114621","DOIUrl":"10.1016/j.mcat.2024.114621","url":null,"abstract":"<div><div>Significant strides have been undertaken to catalyze the production of ethanol from syngas, yet the challenge remains in developing catalysts that simultaneously exhibit high activity and selectivity. In this study, we designed a high-performance Rh-Mn catalyst. The CO conversion of finally screened 1Rh1Mn/TiO<sub>2</sub> catalyst is 51.8 %, and the total alcohol selectivity and ethanol yield are 72.1 % and 24.1 % respectively. This is the highest ethanol yield reported to date for Rh-based catalysts. Additionally, this catalyst also kept good stability. The outstanding performance is attributed to the fact that Mn facilitates the formation of Rh<sup>+</sup> active sites, the process of CO insertion, and the generation of CH<sub>3</sub>CHO and CH<sub>3</sub>CO species—critical intermediates in ethanol production. In contrast, the unpromoted 1Rh/TiO<sub>2</sub> catalyst showed poor ethanol selectivity and mainly produced the Rh<sup>0</sup> species, whereas the 1Rh1Mn/TiO<sub>2</sub> catalyst with the addition of Mn showed an increase in total alcohol and ethanol selectivity of 26.5 % and 31.3 %, respectively, as well as a reduction in CO<sub>2</sub> of 50.4 %. In addition, we elucidated the CO<sub>2</sub> generation and conversion pathways in the syngas to ethanol process, which is important for the effective utilization of carbon resources.</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"569 ","pages":"Article 114621"},"PeriodicalIF":3.9,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554858","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 : 2024-10-18DOI: 10.1016/j.mcat.2024.114622
Chenlin Wei , Weitao Wang , Huan Wang , Jiaqi Zhu , Zhen-Hong He , Yangmin Ma , Nianwen Guo , Zhao-Tie Liu
Furfural and 5-hydroxymethylfurfural obtained from sugars can be transformed into various chemicals. Conversion of sugars to furfural and 5-hydroxymethylfurfural are the typical reactions for the biomass feedstock transformation. In this study, a charcoal-based catalyst with acidic sites of Lewis and Brønsted acids was prepared to achieve an effective conversion of biomass sugars (xylose, glucose, and fructose) to furan compounds. By loading zirconium dioxide on the charcoal-based materials and then sulfonating it, the Lewis and Brønsted acids in the prepared solid acidic catalyst can be regulated to a suitable ratio. Under the optimal reaction condition, the furfural yield from xylose was 94.9 %, and the 5-hydroxymethylfurfural yields from glucose and fructose were 72.2 % and 99.9 %, respectively. Furthermore, a variety of sugars and agricultural wastes can be transformed into the corresponding furfural and 5-hydroxymethylfurfural in satisfactory yields over the catalyst.
{"title":"ZrO2 modified sulfonated charcoal-based catalysts for hydrolysis of biomass sugars and agricultural residues","authors":"Chenlin Wei , Weitao Wang , Huan Wang , Jiaqi Zhu , Zhen-Hong He , Yangmin Ma , Nianwen Guo , Zhao-Tie Liu","doi":"10.1016/j.mcat.2024.114622","DOIUrl":"10.1016/j.mcat.2024.114622","url":null,"abstract":"<div><div>Furfural and 5-hydroxymethylfurfural obtained from sugars can be transformed into various chemicals. Conversion of sugars to furfural and 5-hydroxymethylfurfural are the typical reactions for the biomass feedstock transformation. In this study, a charcoal-based catalyst with acidic sites of Lewis and Brønsted acids was prepared to achieve an effective conversion of biomass sugars (xylose, glucose, and fructose) to furan compounds. By loading zirconium dioxide on the charcoal-based materials and then sulfonating it, the Lewis and Brønsted acids in the prepared solid acidic catalyst can be regulated to a suitable ratio. Under the optimal reaction condition, the furfural yield from xylose was 94.9 %, and the 5-hydroxymethylfurfural yields from glucose and fructose were 72.2 % and 99.9 %, respectively. Furthermore, a variety of sugars and agricultural wastes can be transformed into the corresponding furfural and 5-hydroxymethylfurfural in satisfactory yields over the catalyst.</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"569 ","pages":"Article 114622"},"PeriodicalIF":3.9,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554855","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 : 2024-10-18DOI: 10.1016/j.mcat.2024.114619
Cuimei Li , Dong Cao , Dandan Guo , Chun-Ran Chang
Single-atom catalysts (SACs) have great potential for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) since their high atomic utilization and strong metal–support interactions. Herein, we develop TM@C5N4 (TM = Fe, Co, Ni, Ru, Rh, Pd, Os, Ir and Pt) catalysts via embedding Group VⅢ TM in holey C5N4 substrate and further evaluate their electrocatalytic activity using density functional theory (DFT) calculations. Systematical studies indicate that Fe@C5N4, Pd@C5N4 and Ir@C5N4 catalysts all exhibit excellent HER performance, which mainly because of their small ΔGH* values of 0.101 eV, -0.114 eV and 0.070 eV, respectively. In parallel, Rh@C5N4 and Ir@C5N4 possess high OER activity along with low overpotential of 0.50 V, which is superior to the commercial IrO2 catalyst (0.56 V). Obviously, Ir@C5N4 could be utilized as bifunctional electrocatalysts both HER and OER in water splitting. Furthermore, we analyze their correlative catalytic mechanisms using the molecular orbitals. Besides, biaxial strain modulation could effectively regulate the catalytic activity of HER and OER. Particularly, 2 % biaxial tensile strain could bring Ir@C5N4 superb HER/OER catalytic performance. Finally, we anticipate that this strain engineering would provide a new perspective for developing high-performance SACs for water splitting.
单原子催化剂（SAC）具有原子利用率高、金属与载体相互作用强等特点，因此在氢进化反应（HER）和氧进化反应（OER）中具有巨大潜力。在此，我们通过将 V Ⅲ族 TM 嵌入孔状 C5N4 衬底，开发了 TM@C5N4（TM = Fe、Co、Ni、Ru、Rh、Pd、Os、Ir 和 Pt）催化剂，并利用密度泛函理论（DFT）计算进一步评估了它们的电催化活性。系统研究表明，Fe@C5N4、Pd@C5N4 和 Ir@C5N4 催化剂均表现出优异的 HER 性能，这主要是因为它们的 ΔGH* 值较小，分别为 0.101 eV、-0.114 eV 和 0.070 eV。同时，Rh@C5N4 和 Ir@C5N4 具有较高的 OER 活性和较低的过电位（0.50 V），优于商用 IrO2 催化剂（0.56 V）。显然，Ir@C5N4 可作为双功能电催化剂，同时具有 HER 和 OER 两种水分离活性。此外，我们还利用分子轨道分析了它们的相关催化机理。此外，双轴应变调节能有效调节 HER 和 OER 的催化活性。特别是 2% 的双轴拉伸应变可以使 Ir@C5N4 具有极佳的 HER/OER 催化性能。最后，我们预计这种应变工程将为开发用于水分离的高性能 SAC 提供一个新的视角。
{"title":"Computational screening of Group VⅢ@C5N4 single-atom electrocatalysts for overall water splitting","authors":"Cuimei Li , Dong Cao , Dandan Guo , Chun-Ran Chang","doi":"10.1016/j.mcat.2024.114619","DOIUrl":"10.1016/j.mcat.2024.114619","url":null,"abstract":"<div><div>Single-atom catalysts (SACs) have great potential for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) since their high atomic utilization and strong metal–support interactions. Herein, we develop TM@C<sub>5</sub>N<sub>4</sub> (TM = Fe, Co, Ni, Ru, Rh, Pd, Os, Ir and Pt) catalysts via embedding Group VⅢ TM in holey C<sub>5</sub>N<sub>4</sub> substrate and further evaluate their electrocatalytic activity using density functional theory (DFT) calculations. Systematical studies indicate that Fe@C<sub>5</sub>N<sub>4</sub>, Pd@C<sub>5</sub>N<sub>4</sub> and Ir@C<sub>5</sub>N<sub>4</sub> catalysts all exhibit excellent HER performance, which mainly because of their small Δ<em>G</em><sub>H*</sub> values of 0.101 eV, -0.114 eV and 0.070 eV, respectively. In parallel, Rh@C<sub>5</sub>N<sub>4</sub> and Ir@C<sub>5</sub>N<sub>4</sub> possess high OER activity along with low overpotential of 0.50 V, which is superior to the commercial IrO<sub>2</sub> catalyst (0.56 V). Obviously, Ir@C<sub>5</sub>N<sub>4</sub> could be utilized as bifunctional electrocatalysts both HER and OER in water splitting. Furthermore, we analyze their correlative catalytic mechanisms using the molecular orbitals. Besides, biaxial strain modulation could effectively regulate the catalytic activity of HER and OER. Particularly, 2 % biaxial tensile strain could bring Ir@C<sub>5</sub>N<sub>4</sub> superb HER/OER catalytic performance. Finally, we anticipate that this strain engineering would provide a new perspective for developing high-performance SACs for water splitting.</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"569 ","pages":"Article 114619"},"PeriodicalIF":3.9,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554856","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 : 2024-10-18DOI: 10.1016/j.mcat.2024.114609
Ming Kong , Heping Liao , Linjiang Song , Shengchao Zhang , Yunchuan Wang , Wei Feng , Zhifang Liu , Xianling Deng , Lu Yao , Handan Zhang
Sulfur poisoning is an intractable challenge for NH3-SCR catalyst. In this issue, the immanent reasons for MnOx-CeO2/Ti-bearing blast furnace slag catalyst deactivation resulting from SO2 were elaborated by catalytic activity evaluation, BET, XRD, XPS, NH3-TPD, H2-TPR and in-situ DRIFTS analysis. Results showed that MnOx-CeO2/Ti-bearing blast furnace slag catalyst followed E-R reaction mechanism and performed 100 % NO conversion at 175 °C, whereas its sulfur resistance was unsatisfactory and the deactivation degree became more severe with SO2 concentration increasing. SO2 reacted with NH3 to generate (NH4)2SO4 and NH4HSO4 deposits, blocking catalyst pores and covering active sites. SO2 also interacted with MnOx-CeO2 active components to form MnSO4 and Ce2(SO4)3, which restricted the electron transfers of Mn4+/Mnn+ and Ce3+/Ce4+. Besides, the newly formed sulfur-containing acidic sites also competed with the original active sites for NH3 adsorption, thereby hindering the SCR reaction. Physical purging could not realize regeneration of SO2-poisoning catalyst, but hyperthermic treatment was an efficient solution.
{"title":"Insight into SO2 poisoning mechanism of MnOx-CeO2/Ti-bearing blast furnace slag catalyst for low temperature NH3-SCR reaction","authors":"Ming Kong , Heping Liao , Linjiang Song , Shengchao Zhang , Yunchuan Wang , Wei Feng , Zhifang Liu , Xianling Deng , Lu Yao , Handan Zhang","doi":"10.1016/j.mcat.2024.114609","DOIUrl":"10.1016/j.mcat.2024.114609","url":null,"abstract":"<div><div>Sulfur poisoning is an intractable challenge for NH<sub>3</sub>-SCR catalyst. In this issue, the immanent reasons for MnO<sub>x</sub>-CeO<sub>2</sub>/Ti-bearing blast furnace slag catalyst deactivation resulting from SO<sub>2</sub> were elaborated by catalytic activity evaluation, BET, XRD, XPS, NH<sub>3</sub>-TPD, H<sub>2</sub>-TPR and <em>in-situ</em> DRIFTS analysis. Results showed that MnO<sub>x</sub>-CeO<sub>2</sub>/Ti-bearing blast furnace slag catalyst followed E-R reaction mechanism and performed 100 % NO conversion at 175 °C, whereas its sulfur resistance was unsatisfactory and the deactivation degree became more severe with SO<sub>2</sub> concentration increasing. SO<sub>2</sub> reacted with NH<sub>3</sub> to generate (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub> and NH<sub>4</sub>HSO<sub>4</sub> deposits, blocking catalyst pores and covering active sites. SO<sub>2</sub> also interacted with MnO<sub>x</sub>-CeO<sub>2</sub> active components to form MnSO<sub>4</sub> and Ce<sub>2</sub>(SO<sub>4</sub>)<sub>3</sub>, which restricted the electron transfers of Mn<sup>4+</sup>/Mn<sup>n+</sup> and Ce<sup>3+</sup>/Ce<sup>4+</sup>. Besides, the newly formed sulfur-containing acidic sites also competed with the original active sites for NH<sub>3</sub> adsorption, thereby hindering the SCR reaction. Physical purging could not realize regeneration of SO<sub>2</sub>-poisoning catalyst, but hyperthermic treatment was an efficient solution.</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"569 ","pages":"Article 114609"},"PeriodicalIF":3.9,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554857","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 : 2024-10-18DOI: 10.1016/j.mcat.2024.114617
Subhashree Mishra , Neha Kamal , Arup Kumar De , Indrajit Sinha , Amulya Prasad Panda , R.K. Dey , Rajaram Bal
Conversion of furfural (FFL) to furfuryl alcohol (FOL) using nickel loaded modified red mud (Ni-MRM) was developed with an aim to eliminate toxic Cu-Cr catalyst or precious metal catalyst currently used industrially. Ni-MRM was characterized using various advanced instruments such as XRD, TEM, TPR, BET and XPS. Thermal stability of the material was computed using Kissinger-Akahira-Sonuse (KAS) model. Ni-MRM catalytic activity was studied with variation of parameters. A 15 % Ni-loading on MRM (Ni(15 %)-MRM) shows significant product selectivity (>90 %) in optimized reaction conditions. Density functional theory (DFT) was used for calculation of adsorption energy, charge of the metal at the material active sites. The theoretical calculation shows that H2 molecule adsorbed upon electron rich Ni surface facilitate bond cleavage to initiate the reaction with adsorbed furfural molecule. Ni-MRM could be reused without significant loss of material catalytic activity for production of furfuryl alcohol. The work also shows effective utilization of properties of red mud for selective transformation of furfural, a bio-renewable material, to value added products.
{"title":"Use of red-mud (MRM) in industrial catalysis: Selective conversion of biomass derived furfural to furfuryl alcohol using Ni-MRM – preparation, characterization and activity studies – elucidating mechanism of hydrogenation using DFT","authors":"Subhashree Mishra , Neha Kamal , Arup Kumar De , Indrajit Sinha , Amulya Prasad Panda , R.K. Dey , Rajaram Bal","doi":"10.1016/j.mcat.2024.114617","DOIUrl":"10.1016/j.mcat.2024.114617","url":null,"abstract":"<div><div>Conversion of furfural (FFL) to furfuryl alcohol (FOL) using nickel loaded modified red mud (Ni-MRM) was developed with an aim to eliminate toxic Cu-Cr catalyst or precious metal catalyst currently used industrially. Ni-MRM was characterized using various advanced instruments such as XRD, TEM, TPR, BET and XPS. Thermal stability of the material was computed using Kissinger-Akahira-Sonuse (KAS) model. Ni-MRM catalytic activity was studied with variation of parameters. A 15 % Ni-loading on MRM (Ni(15 %)-MRM) shows significant product selectivity (>90 %) in optimized reaction conditions. Density functional theory (DFT) was used for calculation of adsorption energy, charge of the metal at the material active sites. The theoretical calculation shows that H<sub>2</sub> molecule adsorbed upon electron rich Ni surface facilitate bond cleavage to initiate the reaction with adsorbed furfural molecule. Ni-MRM could be reused without significant loss of material catalytic activity for production of furfuryl alcohol. The work also shows effective utilization of properties of red mud for selective transformation of furfural, a bio-renewable material, to value added products.</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"569 ","pages":"Article 114617"},"PeriodicalIF":3.9,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554800","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 primary focus of the present study is to develop a zeolite-based catalyst that enhances Lewis acidity for catalysing 5-hydroxymethylfurfural (HMF) oxidation. The study modifies the parent H-ZSM-5 (H-Z) via desilication followed by Ru impregnation. The results show that RuZS90 (Ru impregnated on desilicated H-Z for 90 min) exhibits higher catalytic activity for the HMF oxidation than Ru impregnated on parent H-Z. NH3-temperature programmed desorption (TPD) results indicate that RuZS90 possesses more than 2.6 and 2.3 times higher total acidity than H-Z and RuH-Z, contributing to the higher catalytic activity. A poisoning study with potassium thiocyanate (KSCN), which passivates Lewis acidic sites, suggests that RuZS90 yields no considerable oxidised furanic products, confirming the crucial role of Lewis acidic sites. The NH3-DRIFT study further corroborates that RuZS90 contains more enhanced Lewis acidic sites than the parent H-Z, playing a vital role in the oxidation of HMF.
{"title":"Enhanced Lewis acidity on modified H-ZSM-5 catalysed 5-hydroxymethylfurfural oxidation in aqueous solvent","authors":"Rahul Gautam, Neeraj Sharma, Kanika Saini, Shunmugavel Saravanamurugan","doi":"10.1016/j.mcat.2024.114610","DOIUrl":"10.1016/j.mcat.2024.114610","url":null,"abstract":"<div><div>The primary focus of the present study is to develop a zeolite-based catalyst that enhances Lewis acidity for catalysing 5-hydroxymethylfurfural (HMF) oxidation. The study modifies the parent H-ZSM-5 (H-Z) via desilication followed by Ru impregnation. The results show that RuZS<sub>90</sub> (Ru impregnated on desilicated H-Z for 90 min) exhibits higher catalytic activity for the HMF oxidation than Ru impregnated on parent H-Z. NH<sub>3</sub>-temperature programmed desorption (TPD) results indicate that RuZS<sub>90</sub> possesses more than 2.6 and 2.3 times higher total acidity than H-Z and RuH-Z, contributing to the higher catalytic activity. A poisoning study with potassium thiocyanate (KSCN), which passivates Lewis acidic sites, suggests that RuZS<sub>90</sub> yields no considerable oxidised furanic products, confirming the crucial role of Lewis acidic sites. The NH<sub>3</sub>-DRIFT study further corroborates that RuZS<sub>90</sub> contains more enhanced Lewis acidic sites than the parent H-Z, playing a vital role in the oxidation of HMF.</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"569 ","pages":"Article 114610"},"PeriodicalIF":3.9,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142446444","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 : 2024-10-17DOI: 10.1016/j.mcat.2024.114616
Sohaib Hameed , Xiaoli Pan , Weixiang Guan , Aiqin Wang
The production of 2,5-furandicarboxylic acid (FDCA), a promising biodegradable alternative to fossil-based terephthalic acid (PTA), from biomass-derived 5-hydroxymethylfurfural (HMF) is of significant importance. A major challenge is to develop an effective non-precious metal catalyst system that does not require a homogeneous base. In this study, we present a noble-metal-free Co-N-C catalyst, derived from the pyrolysis of cobalt-phenanthroline complexes on a carbon support. This catalyst demonstrates exceptional performance, achieving a FDCA yield of 99.9 % and maintaining reusability for up to five catalytic cycles in the base-free oxidation of HMF to FDCA under mild conditions. Through controlled experiments and comprehensive characterizations, we propose that the active sites in the Co-N-C catalyst are Co single atoms bonded to nitrogen within graphitic sheets. This approach provides valuable insights into the exact nature of the active sites in such noble-metal-free M-N-C catalysts designed for biomass conversion
{"title":"Co-N-C catalyst with single atom active sites for base-free aerobic oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid under mild conditions","authors":"Sohaib Hameed , Xiaoli Pan , Weixiang Guan , Aiqin Wang","doi":"10.1016/j.mcat.2024.114616","DOIUrl":"10.1016/j.mcat.2024.114616","url":null,"abstract":"<div><div>The production of 2,5-furandicarboxylic acid (FDCA), a promising biodegradable alternative to fossil-based terephthalic acid (PTA), from biomass-derived 5-hydroxymethylfurfural (HMF) is of significant importance. A major challenge is to develop an effective non-precious metal catalyst system that does not require a homogeneous base. In this study, we present a noble-metal-free Co-N-C catalyst, derived from the pyrolysis of cobalt-phenanthroline complexes on a carbon support. This catalyst demonstrates exceptional performance, achieving a FDCA yield of 99.9 % and maintaining reusability for up to five catalytic cycles in the base-free oxidation of HMF to FDCA under mild conditions. Through controlled experiments and comprehensive characterizations, we propose that the active sites in the Co-N-C catalyst are Co single atoms bonded to nitrogen within graphitic sheets. This approach provides valuable insights into the exact nature of the active sites in such noble-metal-free M-N-C catalysts designed for biomass conversion</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"569 ","pages":"Article 114616"},"PeriodicalIF":3.9,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142446440","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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