Max Schmallegger, Mathias Wiech, Sebastian Soritz, Miriam de J Velásquez-Hernández, Brigitte Bitschnau, Heidrun Gruber-Woelfler, Georg Gescheidt
Tetrazole moieties are components of various pharmacologically active molecules. Several synthetic protocols for the synthesis of tetrazoles have been developed. Among those, the reaction of organic nitriles with azides catalyzed by Lewis acids (LAs) provides a convenient access. Nevertheless, generally rather harsh reaction conditions have to be utilized for such syntheses. We have developed a simple, solvent-free procedure which allows a convenient isolation of tetrazoles using a heterogeneous catalyst: we show that polystyrene/AlCl3 composites produce tetrazoles at reasonable yields and allow a simple work-up procedure. We have characterized the AlCl3/polystyrene composite (gas sorption, XRD, IR) and investigated its efficacy in the preparation of aryl-substituted tetrazoles. We also have evaluated MgCl2, CuCl2, and ZnCl2 as Lewis-acid catalysts, but they are clearly outperformed by AlCl3 correlating with the Lewis-acid strength on the Gutmann-Beckett scale.
{"title":"Polystyrene-bound AlCl<sub>3</sub> - a catalyst for the solvent-free synthesis of aryl-substituted tetrazoles.","authors":"Max Schmallegger, Mathias Wiech, Sebastian Soritz, Miriam de J Velásquez-Hernández, Brigitte Bitschnau, Heidrun Gruber-Woelfler, Georg Gescheidt","doi":"10.1039/d4cy01215a","DOIUrl":"10.1039/d4cy01215a","url":null,"abstract":"<p><p>Tetrazole moieties are components of various pharmacologically active molecules. Several synthetic protocols for the synthesis of tetrazoles have been developed. Among those, the reaction of organic nitriles with azides catalyzed by Lewis acids (LAs) provides a convenient access. Nevertheless, generally rather harsh reaction conditions have to be utilized for such syntheses. We have developed a simple, solvent-free procedure which allows a convenient isolation of tetrazoles using a heterogeneous catalyst: we show that polystyrene/AlCl<sub>3</sub> composites produce tetrazoles at reasonable yields and allow a simple work-up procedure. We have characterized the AlCl<sub>3</sub>/polystyrene composite (gas sorption, XRD, IR) and investigated its efficacy in the preparation of aryl-substituted tetrazoles. We also have evaluated MgCl<sub>2</sub>, CuCl<sub>2</sub>, and ZnCl<sub>2</sub> as Lewis-acid catalysts, but they are clearly outperformed by AlCl<sub>3</sub> correlating with the Lewis-acid strength on the Gutmann-Beckett scale.</p>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11815551/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143431921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The water–gas shift (WGS) reaction is critical for ensuring the purity of hydrogen in industrial hydrogen production. Due to thermodynamic limitations at high temperatures, achieving complete CO conversion at low temperatures is more feasible, although it presents a significant challenge. Currently, low-temperature WGS catalysts are mainly focused on supported noble-metal catalysts. However, an increasing number of studies have shown that transition metal carbides and nitrides, due to their noble-metal-like properties, can exhibit significant potential for achieving high performance in the low-temperature WGS reaction. In this review, we discuss the reaction performance, composition, crystal structure, preparation methods, and reaction mechanisms of the state-of-the-art transition metal carbides and nitrides. We then propose the challenges and opportunities these materials face in the low-temperature WGS reaction. We hope this review can provide valuable insights and inspiration for future research on transition metal carbides/nitrides catalysts, which can promote the development of sustainable hydrogen production technologies.
{"title":"Noble-metal-like catalysts of carbide and nitride for the low-temperature water–gas shift reaction: a review","authors":"Tongrui Shao , Lichao Li , Jian Lin","doi":"10.1039/d4cy01298d","DOIUrl":"10.1039/d4cy01298d","url":null,"abstract":"<div><div>The water–gas shift (WGS) reaction is critical for ensuring the purity of hydrogen in industrial hydrogen production. Due to thermodynamic limitations at high temperatures, achieving complete CO conversion at low temperatures is more feasible, although it presents a significant challenge. Currently, low-temperature WGS catalysts are mainly focused on supported noble-metal catalysts. However, an increasing number of studies have shown that transition metal carbides and nitrides, due to their noble-metal-like properties, can exhibit significant potential for achieving high performance in the low-temperature WGS reaction. In this review, we discuss the reaction performance, composition, crystal structure, preparation methods, and reaction mechanisms of the state-of-the-art transition metal carbides and nitrides. We then propose the challenges and opportunities these materials face in the low-temperature WGS reaction. We hope this review can provide valuable insights and inspiration for future research on transition metal carbides/nitrides catalysts, which can promote the development of sustainable hydrogen production technologies.</div></div>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":"15 5","pages":"Pages 1339-1356"},"PeriodicalIF":4.4,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143535641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhangqian Wei , Yuanjie Bao , Yuchen Wang , Shenggang Li
Hydrogenation of CO2 into value-added chemicals and fuels, such as methanol, is a promising solution to mitigate the greenhouse effect, and In2O3-based catalysts have shown high activity and stability in the CO2 hydrogenation reactions. In this study, the effects of oxygen vacancy formation energy and bulk Pt doping on CO2 reactivity and methanol selectivity in CO2 hydrogenation catalyzed by In2O3 and Pt-doped In2O3 were studied using density functional theory (DFT) calculations and microkinetic simulations. Upon oxygen vacancy formation, the number of electrons lost by the In atoms surrounding the oxygen vacancies decreased substantially, which correlated with the oxygen vacancy formation energy, and Pt doping further increased the oxygen vacancy formation energy. DFT-based microkinetic simulations revealed that Pt doping also enhanced the overall reaction rate and methanol selectivity. Among the different surface oxygen vacancy sites, no methanol was predicted to be formed for VO3 and VO6 between 473 K and 673 K; however, the methanol selectivities for Pt-VO3 and Pt-VO6 were calculated to be 50% at 473 K. Nevertheless, the reactivities of these oxygen vacancy sites were found to be lower than those of the previously studied VO7 and Pt-VO7, further confirming our previous conclusions. Degree of rate control (DRC) calculations showed that the fast direct dissociation of CO2 to CO at Pt-VO3, Pt-VO6 and Pt-VO7 inhibited methanol formation, especially at relatively high reaction temperatures. This study sheds new physical insights into the quantitative structure–activity relationship between the oxygen vacancy formation energy and the catalytic performance of the In2O3-based catalysts and reveals the effect of bulk Pt doping on the catalytic activity of the In2O3 catalyst for CO2 hydrogenation reaction.
{"title":"Effects of oxygen vacancy formation energy and Pt doping on the CO2 hydrogenation activity of In2O3 catalysts†","authors":"Zhangqian Wei , Yuanjie Bao , Yuchen Wang , Shenggang Li","doi":"10.1039/d4cy01439a","DOIUrl":"10.1039/d4cy01439a","url":null,"abstract":"<div><div>Hydrogenation of CO<sub>2</sub> into value-added chemicals and fuels, such as methanol, is a promising solution to mitigate the greenhouse effect, and In<sub>2</sub>O<sub>3</sub>-based catalysts have shown high activity and stability in the CO<sub>2</sub> hydrogenation reactions. In this study, the effects of oxygen vacancy formation energy and bulk Pt doping on CO<sub>2</sub> reactivity and methanol selectivity in CO<sub>2</sub> hydrogenation catalyzed by In<sub>2</sub>O<sub>3</sub> and Pt-doped In<sub>2</sub>O<sub>3</sub> were studied using density functional theory (DFT) calculations and microkinetic simulations. Upon oxygen vacancy formation, the number of electrons lost by the In atoms surrounding the oxygen vacancies decreased substantially, which correlated with the oxygen vacancy formation energy, and Pt doping further increased the oxygen vacancy formation energy. DFT-based microkinetic simulations revealed that Pt doping also enhanced the overall reaction rate and methanol selectivity. Among the different surface oxygen vacancy sites, no methanol was predicted to be formed for V<sub>O3</sub> and V<sub>O6</sub> between 473 K and 673 K; however, the methanol selectivities for Pt-V<sub>O3</sub> and Pt-V<sub>O6</sub> were calculated to be 50% at 473 K. Nevertheless, the reactivities of these oxygen vacancy sites were found to be lower than those of the previously studied V<sub>O7</sub> and Pt-V<sub>O7</sub>, further confirming our previous conclusions. Degree of rate control (DRC) calculations showed that the fast direct dissociation of CO<sub>2</sub> to CO at Pt-V<sub>O3</sub>, Pt-V<sub>O6</sub> and Pt-V<sub>O7</sub> inhibited methanol formation, especially at relatively high reaction temperatures. This study sheds new physical insights into the quantitative structure–activity relationship between the oxygen vacancy formation energy and the catalytic performance of the In<sub>2</sub>O<sub>3</sub>-based catalysts and reveals the effect of bulk Pt doping on the catalytic activity of the In<sub>2</sub>O<sub>3</sub> catalyst for CO<sub>2</sub> hydrogenation reaction.</div></div>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":"15 5","pages":"Pages 1538-1546"},"PeriodicalIF":4.4,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143535665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lei Qin , Yue Qiao , Miaomiao Xu , Wei Li , Shi-Peng Sun , Yonghong Hu , Lili Zhao
γ-Lactams are present in numerous natural and synthetic bioactive compounds, exhibiting a wide range of biological activities. Compared to traditional multi-step synthesis, intramolecular amination of aliphatic amides can directly construct valuable γ-lactam motifs from abundant amino acid precursors. Recently, Yu and coworkers reported novel 2-pyridone ligand-facilitated Pd(ii)-catalyzed γ-C(sp3)–H lactamization of amino acid-derived natural amides. This protocol is notable for its use of practical and environmentally friendly tert-butyl hydroperoxide (TBHP) as the sole oxidant and its broad substrate scope. In this study, we present a comprehensive computational mechanistic study on the Pd(ii)-catalyzed γ-C(sp3)–H lactamization, elucidating the key roles of the oxidant TBHP and Pd oxidation state transformations. The entire catalytic process can be divided into three stages: (i) the formation of actual active species (OAc)Pd–L1 followed by γ-C(sp3)–H bond activation generating the six-membered-metallacycle Pd(ii) intermediate IM4; (ii) with the assistance of oxidant TBHP, the C–N bond annulation occurs to complete the γ-lactamization process; (iii) product formation and active species (OAc)Pd–L1 regeneration for the next catalytic cycle. Each stage is both kinetically and thermodynamically feasible. Intermediate 1/3Pd3(OAc)6 to the IM2 step, with a barrier of 25.4 kcal mol−1, should be the rate-determining step (RDS) in the whole catalysis. Based on mechanistic study, new pyridone ligands (i.e., L3 and L4) affording lower free energy barriers were further rationally designed, which will help to improve current catalytic systems and facilitate the development of new Pd(ii)-catalyzed γ-C(sp3)–H lactamization reactions.
{"title":"A computational mechanistic study on the Pd(ii)-catalyzed γ-C(sp3)–H lactamization and further rational design†","authors":"Lei Qin , Yue Qiao , Miaomiao Xu , Wei Li , Shi-Peng Sun , Yonghong Hu , Lili Zhao","doi":"10.1039/d4cy01302f","DOIUrl":"10.1039/d4cy01302f","url":null,"abstract":"<div><div>γ-Lactams are present in numerous natural and synthetic bioactive compounds, exhibiting a wide range of biological activities. Compared to traditional multi-step synthesis, intramolecular amination of aliphatic amides can directly construct valuable γ-lactam motifs from abundant amino acid precursors. Recently, Yu and coworkers reported novel 2-pyridone ligand-facilitated Pd(<span>ii</span>)-catalyzed γ-C(sp<sup>3</sup>)–H lactamization of amino acid-derived natural amides. This protocol is notable for its use of practical and environmentally friendly <em>tert</em>-butyl hydroperoxide (TBHP) as the sole oxidant and its broad substrate scope. In this study, we present a comprehensive computational mechanistic study on the Pd(<span>ii</span>)-catalyzed γ-C(sp<sup>3</sup>)–H lactamization, elucidating the key roles of the oxidant TBHP and Pd oxidation state transformations. The entire catalytic process can be divided into three stages: (i) the formation of actual active species (OAc)Pd–L1 followed by γ-C(sp<sup>3</sup>)–H bond activation generating the six-membered-metallacycle Pd(<span>ii</span>) intermediate <strong>IM4</strong>; (ii) with the assistance of oxidant TBHP, the C–N bond annulation occurs to complete the γ-lactamization process; (iii) product formation and active species (OAc)Pd–L1 regeneration for the next catalytic cycle. Each stage is both kinetically and thermodynamically feasible. Intermediate 1/3Pd<sub>3</sub>(OAc)<sub>6</sub> to the <strong>IM2</strong> step, with a barrier of 25.4 kcal mol<sup>−1</sup>, should be the rate-determining step (RDS) in the whole catalysis. Based on mechanistic study, new pyridone ligands (<em>i.e.</em>, <strong>L3</strong> and <strong>L4</strong>) affording lower free energy barriers were further rationally designed, which will help to improve current catalytic systems and facilitate the development of new Pd(<span>ii</span>)-catalyzed γ-C(sp<sup>3</sup>)–H lactamization reactions.</div></div>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":"15 5","pages":"Pages 1653-1663"},"PeriodicalIF":4.4,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143535669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Weiwen Yan , Menghui Liu , Mengxing Li , Liangkai Xu , Chang-jun Liu
CO2 hydrogenation to methane has drawn increasing interest in recent years. Significant efforts are being made to find a catalyst with superior catalytic performance at low temperatures. In this work, a highly dispersed Ru/CeZrO2 catalyst with a Ce/Zr molar ratio of 4/1 was prepared via the decomposition of a ruthenium precursor by energetic species (such as electrons and radicals) from a dielectric barrier discharge (DBD) plasma, operated at about 150 °C. This was followed by thermal hydrogen reduction, resulting in dramatically enhanced activity and stability. For instance, at 275 °C, the methane formation rate on the plasma-decomposed catalyst was found to be about twice that of the catalyst prepared by the thermal decomposition of ruthenium precursor. The plasma-decomposed catalyst exhibited higher dispersion of Ru nanoparticles, enhanced electronic metal–support interactions and improved hydrogen dissociation ability, further facilitating hydrogen spillover from Ru to the surface of CeZrO2 support. Thus, the plasma decomposition caused more surface oxygen vacancies, providing additional adsorption sites for CO2. Analyses via in situ diffuse reflectance infrared Fourier transform spectroscopy revealed that CO2 methanation followed the HCOO* and CO* routes on both catalysts, while the plasma decomposition treatment mainly facilitated catalytic performance at low temperatures by accelerating the formation and consumption of HCOO* in the formate route.
{"title":"Preparation and characterization of a highly dispersed Ru/CeZrO2 catalyst for CO2 methanation with improved activity†","authors":"Weiwen Yan , Menghui Liu , Mengxing Li , Liangkai Xu , Chang-jun Liu","doi":"10.1039/d4cy01332h","DOIUrl":"10.1039/d4cy01332h","url":null,"abstract":"<div><div>CO<sub>2</sub> hydrogenation to methane has drawn increasing interest in recent years. Significant efforts are being made to find a catalyst with superior catalytic performance at low temperatures. In this work, a highly dispersed Ru/CeZrO<sub>2</sub> catalyst with a Ce/Zr molar ratio of 4/1 was prepared <em>via</em> the decomposition of a ruthenium precursor by energetic species (such as electrons and radicals) from a dielectric barrier discharge (DBD) plasma, operated at about 150 °C. This was followed by thermal hydrogen reduction, resulting in dramatically enhanced activity and stability. For instance, at 275 °C, the methane formation rate on the plasma-decomposed catalyst was found to be about twice that of the catalyst prepared by the thermal decomposition of ruthenium precursor. The plasma-decomposed catalyst exhibited higher dispersion of Ru nanoparticles, enhanced electronic metal–support interactions and improved hydrogen dissociation ability, further facilitating hydrogen spillover from Ru to the surface of CeZrO<sub>2</sub> support. Thus, the plasma decomposition caused more surface oxygen vacancies, providing additional adsorption sites for CO<sub>2</sub>. Analyses <em>via in situ</em> diffuse reflectance infrared Fourier transform spectroscopy revealed that CO<sub>2</sub> methanation followed the HCOO* and CO* routes on both catalysts, while the plasma decomposition treatment mainly facilitated catalytic performance at low temperatures by accelerating the formation and consumption of HCOO* in the formate route.</div></div>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":"15 5","pages":"Pages 1557-1566"},"PeriodicalIF":4.4,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143535602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tasmina Khandaker , Md Al Amin Mia Anik , Ananya Nandi , Tasniqul Islam , Md Mohibul Islam , Md Kamrul Hasan , Palash Kumar Dhar , M. Abdul Latif , Muhammad Sarwar Hossain
Achieving carbon neutrality and mitigating global warming necessitate a shift from fossil fuels to renewable energy sources. This review explores the pivotal role of polymeric gels in advancing energy conversion and storage technologies, highlighting their potential in reducing CO2 emissions. Gels exhibit unique properties such as thermal conductivity, mechanical resilience, and catalytic efficiency, making them promising candidates for energy applications like photovoltaic cells, batteries, and electrocatalytic systems. Their flexible structure, large surface areas, and porous nature significantly improve redox reaction efficiency and energy storage capacity. Recent innovations, especially hybrid gels combining conducting polymers and nanoparticles, have enhanced catalytic performance, electrical conductivity, and durability, offering more sustainable energy solutions. This review thoroughly examines the synthesis methods, structural properties, and performance metrics of gel materials, focusing on their applications in fuel cells, batteries, and supercapacitors. It also addresses the mechanisms behind energy conversion facilitated by these materials and discusses challenges related to scalability and long-term durability. By providing a comprehensive overview of recent advancements, this review aims to guide future research and drive technological progress in the field of sustainable energy, positioning gel catalysts as key components in the transition to cleaner, more efficient energy systems.
{"title":"Recent progress in gel catalysts: boosting efficiency for sustainable energy applications","authors":"Tasmina Khandaker , Md Al Amin Mia Anik , Ananya Nandi , Tasniqul Islam , Md Mohibul Islam , Md Kamrul Hasan , Palash Kumar Dhar , M. Abdul Latif , Muhammad Sarwar Hossain","doi":"10.1039/d4cy01171f","DOIUrl":"10.1039/d4cy01171f","url":null,"abstract":"<div><div>Achieving carbon neutrality and mitigating global warming necessitate a shift from fossil fuels to renewable energy sources. This review explores the pivotal role of polymeric gels in advancing energy conversion and storage technologies, highlighting their potential in reducing CO<sub>2</sub> emissions. Gels exhibit unique properties such as thermal conductivity, mechanical resilience, and catalytic efficiency, making them promising candidates for energy applications like photovoltaic cells, batteries, and electrocatalytic systems. Their flexible structure, large surface areas, and porous nature significantly improve redox reaction efficiency and energy storage capacity. Recent innovations, especially hybrid gels combining conducting polymers and nanoparticles, have enhanced catalytic performance, electrical conductivity, and durability, offering more sustainable energy solutions. This review thoroughly examines the synthesis methods, structural properties, and performance metrics of gel materials, focusing on their applications in fuel cells, batteries, and supercapacitors. It also addresses the mechanisms behind energy conversion facilitated by these materials and discusses challenges related to scalability and long-term durability. By providing a comprehensive overview of recent advancements, this review aims to guide future research and drive technological progress in the field of sustainable energy, positioning gel catalysts as key components in the transition to cleaner, more efficient energy systems.</div></div>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":"15 5","pages":"Pages 1357-1389"},"PeriodicalIF":4.4,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143535642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aleksandra Jankowska , Klaudia Fidowicz , Małgorzata Rutkowska , Andrzej Kowalczyk , Marek Michalik , Lucjan Chmielarz
Silica–alumina MCM-22 zeolite and its cerium-doped analogue (Ce-MCM-22) were obtained by one-pot synthesis. Additionally, the layered precursor of Ce-MCM-22 was subjected to delamination and pillaring procedures, resulting in the formation of Ce-ITQ-2 and Ce-MCM-36, respectively. The obtained micro- and micro-mesoporous supports were modified with copper cations by the ion-exchange method and tested as catalysts for NO conversion with ammonia. The zeolitic samples were characterized with respect to their chemical composition (ICP-OES), texture (low-temperature N2-sorption), structure (XRD, FT-IR, UV-vis-DR), surface acidity (NH3-TPD) and reducibility (H2-TPR). Cu-functionalized zeolites were found to be active and selective catalysts for the selective catalytic reduction of nitrogen oxides with ammonia (NH3-SCR) in the low-temperature range, effectively operating between 225 and 375 °C. The influence of bimodal porosity on the catalytic efficiency was observed when the space velocity of the reaction increased. The samples doped with cerium were more active than copper-modified silica–alumina MCM-22 in the process of NO-to-NO2 oxidation, which is an important step in the fast-SCR process. The synergistic interaction of cerium–copper species together with a more open structure of the delaminated copper-modified sample (Cu–Ce-ITQ-2) influenced its activity in low-temperature NO conversion under humid reaction conditions.
{"title":"Low-temperature NO conversion with NH3 over cerium-doped MWW derivatives activated with copper species†","authors":"Aleksandra Jankowska , Klaudia Fidowicz , Małgorzata Rutkowska , Andrzej Kowalczyk , Marek Michalik , Lucjan Chmielarz","doi":"10.1039/d4cy01232a","DOIUrl":"10.1039/d4cy01232a","url":null,"abstract":"<div><div>Silica–alumina MCM-22 zeolite and its cerium-doped analogue (Ce-MCM-22) were obtained by one-pot synthesis. Additionally, the layered precursor of Ce-MCM-22 was subjected to delamination and pillaring procedures, resulting in the formation of Ce-ITQ-2 and Ce-MCM-36, respectively. The obtained micro- and micro-mesoporous supports were modified with copper cations by the ion-exchange method and tested as catalysts for NO conversion with ammonia. The zeolitic samples were characterized with respect to their chemical composition (ICP-OES), texture (low-temperature N<sub>2</sub>-sorption), structure (XRD, FT-IR, UV-vis-DR), surface acidity (NH<sub>3</sub>-TPD) and reducibility (H<sub>2</sub>-TPR). Cu-functionalized zeolites were found to be active and selective catalysts for the selective catalytic reduction of nitrogen oxides with ammonia (NH<sub>3</sub>-SCR) in the low-temperature range, effectively operating between 225 and 375 °C. The influence of bimodal porosity on the catalytic efficiency was observed when the space velocity of the reaction increased. The samples doped with cerium were more active than copper-modified silica–alumina MCM-22 in the process of NO-to-NO<sub>2</sub> oxidation, which is an important step in the fast-SCR process. The synergistic interaction of cerium–copper species together with a more open structure of the delaminated copper-modified sample (Cu–Ce-ITQ-2) influenced its activity in low-temperature NO conversion under humid reaction conditions.</div></div>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":"15 5","pages":"Pages 1456-1472"},"PeriodicalIF":4.4,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143535648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, the synthesis and catalytic activity of thiol-functionalized copper-deposited porous carbon derived from dry oil palm leaves (Cu/TF-CNS) was investigated for the reduction of aromatic nitro compounds. The procedure to synthesize porous carbon nanospheres involves the pyrolysis of oil palm leaves in a nitrogen atmosphere at 1000 °C. The resulting porous carbon material was further functionalized with thiol groups to facilitate the uniform deposition of copper nanoparticles and serve as an efficient support. Excellent catalytic performance was shown by the Cu/TF-CNS catalyst in reducing aromatic nitro compounds to their corresponding aromatic amines with a low copper loading of only 4 mol% which is an inexpensive non-noble metal in the presence of NaBH4 as a reducing agent and EtOH/H2O as green solvents. The products were identified using 1H NMR spectroscopy. The catalyst was isolated from the reaction mixture and reused upto 10 cycles without any significant loss in the activity. The ICPAES analysis confirmed the successful incorporation of approximately 8.9% Cu during the deposition process and the reusability of the catalyst underscores its efficacy as a sustainable and effective heterogeneous catalyst for nitroarene reduction.
{"title":"Copper-boosted thiol-functionalized carbon nanospheres from biomass: a novel non-noble metal based recoverable catalyst for efficient nitro-to-amine reduction†","authors":"Apoorva Shetty , Braja Gopal Bag , Uraiwan Sirimahachai , Gurumurthy Hegde","doi":"10.1039/d4cy01368a","DOIUrl":"10.1039/d4cy01368a","url":null,"abstract":"<div><div>In this work, the synthesis and catalytic activity of thiol-functionalized copper-deposited porous carbon derived from dry oil palm leaves (Cu/TF-CNS) was investigated for the reduction of aromatic nitro compounds. The procedure to synthesize porous carbon nanospheres involves the pyrolysis of oil palm leaves in a nitrogen atmosphere at 1000 °C. The resulting porous carbon material was further functionalized with thiol groups to facilitate the uniform deposition of copper nanoparticles and serve as an efficient support. Excellent catalytic performance was shown by the Cu/TF-CNS catalyst in reducing aromatic nitro compounds to their corresponding aromatic amines with a low copper loading of only 4 mol% which is an inexpensive non-noble metal in the presence of NaBH<sub>4</sub> as a reducing agent and EtOH/H<sub>2</sub>O as green solvents. The products were identified using <sup>1</sup>H NMR spectroscopy. The catalyst was isolated from the reaction mixture and reused upto 10 cycles without any significant loss in the activity. The ICPAES analysis confirmed the successful incorporation of approximately 8.9% Cu during the deposition process and the reusability of the catalyst underscores its efficacy as a sustainable and effective heterogeneous catalyst for nitroarene reduction.</div></div>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":"15 5","pages":"Pages 1525-1537"},"PeriodicalIF":4.4,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/cy/d4cy01368a?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143535664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shuairen Qian , Zhengwen Li , Xiaohang Sun , Yuxin Chen , Kai Feng , Kaiqi Nie , Binhang Yan , Yi Cheng
Ammonia is one of the most important feedstocks for both fertilizer production and energy carriers. Identifying the appropriate reaction mechanism from the multiple pathways of ammonia synthesis is critical to the rational design of efficient catalysts. However, the low adhesion of nitrogen molecules hinders the observation of the behavior of reaction intermediates and the understanding of the reaction mechanisms. Kinetic analysis is a powerful tool to recognize reaction mechanisms, but it is difficult to expand case-by-case research to target systems. Herein, we establish a framework for the investigation of reaction mechanisms based on kinetic analysis and apply it to ammonia synthesis over a Co3Mo3N bimetallic nitride catalyst. The energetics of elementary reactions calculated by density functional theory (DFT) is used for a microkinetic model to obtain information about reaction mechanisms. Theoretical calculations indicate that the reaction rate via the surface reaction mechanism is much higher than that via the MvK mechanism. Nitrogen-vacancy-generation-induced charge redispersion is the major hindrance to the subsequent hydrogenation of NHx species for the MvK mechanism. This information guides the design and analysis of kinetic experiments. A series of steady-state and transient kinetic experiments demonstrate the dominant role of the dissociation mechanism over associative and MvK mechanisms. The low coverage of surface N species derived from both DFT-based microkinetic simulations and transient kinetic experiments originates from the high energy barrier to N2 dissociation. This work reveals the reaction mechanism of ammonia synthesis over bimetallic nitrides based on both theoretical calculations and experimental results and proposes a new paradigm for elucidating reaction mechanisms in heterogeneous catalysis from a kinetic perspective.
{"title":"Revealing the reaction mechanism of ammonia synthesis over bimetallic nitride catalyst from a kinetic perspective†","authors":"Shuairen Qian , Zhengwen Li , Xiaohang Sun , Yuxin Chen , Kai Feng , Kaiqi Nie , Binhang Yan , Yi Cheng","doi":"10.1039/d4cy01359j","DOIUrl":"10.1039/d4cy01359j","url":null,"abstract":"<div><div>Ammonia is one of the most important feedstocks for both fertilizer production and energy carriers. Identifying the appropriate reaction mechanism from the multiple pathways of ammonia synthesis is critical to the rational design of efficient catalysts. However, the low adhesion of nitrogen molecules hinders the observation of the behavior of reaction intermediates and the understanding of the reaction mechanisms. Kinetic analysis is a powerful tool to recognize reaction mechanisms, but it is difficult to expand case-by-case research to target systems. Herein, we establish a framework for the investigation of reaction mechanisms based on kinetic analysis and apply it to ammonia synthesis over a Co<sub>3</sub>Mo<sub>3</sub>N bimetallic nitride catalyst. The energetics of elementary reactions calculated by density functional theory (DFT) is used for a microkinetic model to obtain information about reaction mechanisms. Theoretical calculations indicate that the reaction rate <em>via</em> the surface reaction mechanism is much higher than that <em>via</em> the MvK mechanism. Nitrogen-vacancy-generation-induced charge redispersion is the major hindrance to the subsequent hydrogenation of NH<sub><em>x</em></sub> species for the MvK mechanism. This information guides the design and analysis of kinetic experiments. A series of steady-state and transient kinetic experiments demonstrate the dominant role of the dissociation mechanism over associative and MvK mechanisms. The low coverage of surface N species derived from both DFT-based microkinetic simulations and transient kinetic experiments originates from the high energy barrier to N<sub>2</sub> dissociation. This work reveals the reaction mechanism of ammonia synthesis over bimetallic nitrides based on both theoretical calculations and experimental results and proposes a new paradigm for elucidating reaction mechanisms in heterogeneous catalysis from a kinetic perspective.</div></div>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":"15 5","pages":"Pages 1644-1652"},"PeriodicalIF":4.4,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/cy/d4cy01359j?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143535668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kai Huang , Taoli Huhe , Haichao Liu , Da-Ming Gao , Yao Zhai
A hierarchically porous and highly effective tantalum phosphate (TaP) solid acidic catalyst was synthesized using a sol–gel method accompanied by phase separation for converting glucose to 5-hydroxymethylfurfural (HMF). The TaP sample formed the TaPO5 phase after calcining at 600 °C (TaP-600) for 4 hours with a surface area of ca. 103 m2 g−1 and an acidity of ca. 0.18 mmolNH3 g−1. The TaP-600 sample had a co-continuous macroporous structure with a regular and orderly pore arrangement, which was conducive to the diffusion of reactants and products, thereby reducing side reactions. The TaP-600 sample can afford an HMF yield of 25.6% by treating with 1.0 wt% glucose at 170 °C in pure water. Using a water–DMSO homogeneous system or a water/MIBK biphasic reaction system can protect HMF from further decomposition, obtaining a HMF yield of 63.8% and 67.1% (mol mol−1), respectively. The TaP-600 sample also showed high catalytic performance at high glucose concentration in the water/MIBK system, e.g. the HMF yields reached 27.5% and 23.7% at glucose concentrations of 15.0 wt% and 20.0 wt%, respectively. The productivity of HMF reached 6.6 × 10−2 mol h−1 kgsolution−1 at an initial glucose concentration of 20.0 wt% in the water/MIBK biphasic system with a catalyst loading (weight ratio of catalyst to glucose) of 10.0 wt%. The TaP-600 sample can retain most of its activity after three catalytic cycles giving an HMF yield of 17.9%. These results demonstrate the significant potential of TaP for industrial-scale HMF production.
{"title":"Synthesis of hierarchically porous tantalum phosphate catalysts by a sol–gel method for transformation of glucose to 5-hydroxymethylfurfural","authors":"Kai Huang , Taoli Huhe , Haichao Liu , Da-Ming Gao , Yao Zhai","doi":"10.1039/d4cy01112k","DOIUrl":"10.1039/d4cy01112k","url":null,"abstract":"<div><div>A hierarchically porous and highly effective tantalum phosphate (TaP) solid acidic catalyst was synthesized using a sol–gel method accompanied by phase separation for converting glucose to 5-hydroxymethylfurfural (HMF). The TaP sample formed the TaPO<sub>5</sub> phase after calcining at 600 °C (TaP-600) for 4 hours with a surface area of <em>ca.</em> 103 m<sup>2</sup> g<sup>−1</sup> and an acidity of <em>ca.</em> 0.18 mmol<sub>NH<sub>3</sub></sub> g<sup>−1</sup>. The TaP-600 sample had a co-continuous macroporous structure with a regular and orderly pore arrangement, which was conducive to the diffusion of reactants and products, thereby reducing side reactions. The TaP-600 sample can afford an HMF yield of 25.6% by treating with 1.0 wt% glucose at 170 °C in pure water. Using a water–DMSO homogeneous system or a water/MIBK biphasic reaction system can protect HMF from further decomposition, obtaining a HMF yield of 63.8% and 67.1% (mol mol<sup>−1</sup>), respectively. The TaP-600 sample also showed high catalytic performance at high glucose concentration in the water/MIBK system, <em>e.g.</em> the HMF yields reached 27.5% and 23.7% at glucose concentrations of 15.0 wt% and 20.0 wt%, respectively. The productivity of HMF reached 6.6 × 10<sup>−2</sup> mol h<sup>−1</sup> kg<sub>solution</sub><sup>−1</sup> at an initial glucose concentration of 20.0 wt% in the water/MIBK biphasic system with a catalyst loading (weight ratio of catalyst to glucose) of 10.0 wt%. The TaP-600 sample can retain most of its activity after three catalytic cycles giving an HMF yield of 17.9%. These results demonstrate the significant potential of TaP for industrial-scale HMF production.</div></div>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":"15 5","pages":"Pages 1567-1580"},"PeriodicalIF":4.4,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143535603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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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