Pub Date : 2024-12-30DOI: 10.1016/j.apcata.2024.120093
Collette L. Nicholas , John P.S. Mowat , Christopher P. Nicholas
Despite its importance and ubiquity, the information contained in powder XRD data for materials in catalysts is often neither fully harnessed nor correctly interpreted. In this Tutorial Review, we aim to provide the wider catalysis community with a brief tutorial on some of the most encountered key aspects of powder XRD instrumentation, sample preparation, data collection, and analysis procedures used to characterize both catalyst active phases and the complex technical bodies used in full-scale commercial reactors. We will emphasize characterization of broad classes of materials including zeolites, MOFs, metal oxides, and metals as well as the technical bodies relevant to large scale catalysis where various crystal sizes, shapes, dimensionalities and mixtures of materials are encountered. We hope that researchers across many fields, including those who are new to powder XRD or for whom XRD is not their primary technique, can become familiar with key diagnostics and therefore be better equipped to interpret them in the context of their samples.
{"title":"Tutorial review on catalyst characterization and materials preparation for x-ray powder diffraction analysis","authors":"Collette L. Nicholas , John P.S. Mowat , Christopher P. Nicholas","doi":"10.1016/j.apcata.2024.120093","DOIUrl":"10.1016/j.apcata.2024.120093","url":null,"abstract":"<div><div>Despite its importance and ubiquity, the information contained in powder XRD data for materials in catalysts is often neither fully harnessed nor correctly interpreted. In this Tutorial Review, we aim to provide the wider catalysis community with a brief tutorial on some of the most encountered key aspects of powder XRD instrumentation, sample preparation, data collection, and analysis procedures used to characterize both catalyst active phases and the complex technical bodies used in full-scale commercial reactors. We will emphasize characterization of broad classes of materials including zeolites, MOFs, metal oxides, and metals as well as the technical bodies relevant to large scale catalysis where various crystal sizes, shapes, dimensionalities and mixtures of materials are encountered. We hope that researchers across many fields, including those who are new to powder XRD or for whom XRD is not their primary technique, can become familiar with key diagnostics and therefore be better equipped to interpret them in the context of their samples.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"692 ","pages":"Article 120093"},"PeriodicalIF":4.7,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136836","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 : 2024-12-27DOI: 10.1016/j.apcata.2024.120091
Kun Wang , Kunlun Li , Shengnan Zhao , Zezhou Ran , Fuqing Wang
To reduce the carbon monoxide (CO) emissions in sintering flue gas, this study employed a catalytic oxidation approach to convert CO into carbon dioxide (CO2) at low temperatures. The Cu-Mn catalysts were synthesized using co-precipitation methods. The effects of various reaction conditions, such as the Cu/Mn ratio and reaction temperatures, on CO catalytic efficiency was investigated. The results indicated that when the Cu/Mn ratio was 1:2, the catalytic efficiency was 98.34 % at approximately 105 °C. Furthermore, the catalysts remained stable after continuous testing. Based on density functional theory (DFT), a model for the adsorption of CO molecules was established. The adsorption characteristics between CuMn2O4 and CO, as well as the changes in surface charge distribution before and after adsorption, were systematically investigated. The research results indicated that the adsorption of CO on the surface of CuMn2O4 is a chemical adsorption process. Among the various adsorption sites, CO exhibits a greater affinity for the Mn-top site, with an adsorption energy of − 1.18 eV. During the adsorption process, some electrons from CO are transferred to the surface of the catalyst, resulting in orbital hybridization. Additionally, this paper investigated the reaction pathways involved in the CO oxidation process. These findings provide new insights for the optimization and screening of catalysts, which are significant for the fields of industrial flue gas purification and catalytic science.
{"title":"Experimental and mechanism investigation on CO catalytic oxidation performance based on CuMn2O4 catalysts","authors":"Kun Wang , Kunlun Li , Shengnan Zhao , Zezhou Ran , Fuqing Wang","doi":"10.1016/j.apcata.2024.120091","DOIUrl":"10.1016/j.apcata.2024.120091","url":null,"abstract":"<div><div>To reduce the carbon monoxide (CO) emissions in sintering flue gas, this study employed a catalytic oxidation approach to convert CO into carbon dioxide (CO<sub>2</sub>) at low temperatures. The Cu<em>-</em>Mn catalysts were synthesized using co-precipitation methods. The effects of various reaction conditions, such as the Cu/Mn ratio and reaction temperatures, on CO catalytic efficiency was investigated. The results indicated that when the Cu/Mn ratio was 1:2, the catalytic efficiency was 98.34 % at approximately 105 °C. Furthermore, the catalysts remained stable after continuous testing. Based on density functional theory (DFT), a model for the adsorption of CO molecules was established. The adsorption characteristics between CuMn<sub>2</sub>O<sub>4</sub> and CO, as well as the changes in surface charge distribution before and after adsorption, were systematically investigated. The research results indicated that the adsorption of CO on the surface of CuMn<sub>2</sub>O<sub>4</sub> is a chemical adsorption process. Among the various adsorption sites, CO exhibits a greater affinity for the Mn-top site, with an adsorption energy of − 1.18 eV. During the adsorption process, some electrons from CO are transferred to the surface of the catalyst, resulting in orbital hybridization. Additionally, this paper investigated the reaction pathways involved in the CO oxidation process. These findings provide new insights for the optimization and screening of catalysts, which are significant for the fields of industrial flue gas purification and catalytic science.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"692 ","pages":"Article 120091"},"PeriodicalIF":4.7,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-19DOI: 10.1016/j.apcata.2024.120079
Lijiao Zhong , Xing Li , Yiquan Zhan , Yongsheng Liu , Kai Yang , Jinbiao Liu , Shiyong Liu , Junzhe Jiang , Liqing Li , Yoshihisa Sakata
Solar-driven hydrogen production through water splitting is currently one of the research hotspots nowadays. Lanthanum titanate (La2Ti2O7) is one kind of layered-structure perovskite photocatalyst and possesses a superior electronic structure for photocatalytic overall water splitting. However, it suffers from several drawbacks, such as poor photo absorption and easy recombination of photogenerated charge carriers. In this study, sodium (Na) ion-doped La2Ti2O7 with plate-like crystal morphology was synthesized by using molten salt synthesis (MSS). The XRD and TEM results indicated that the MSS method enhanced the crystallinity of La2Ti2O7. UV–vis, Raman and EPR spectra disclosed that Na doping through MSS introduced oxygen vacancies. The Na (0.3 mol%)-doped La2Ti2O7 (MSS) provided the optimal hydrogen evolution rate, and the value was 6.43 times greater than that of pure La2Ti2O7 synthesized by traditional solid-state reaction method. The synergistic effect of crystal facet engineering and defect engineering remarkably enhanced the photocatalytic activity of La2Ti2O7.
{"title":"Sodium-doped La2Ti2O7 synthesized by molten salt synthesis method for photocatalytic overall water splitting","authors":"Lijiao Zhong , Xing Li , Yiquan Zhan , Yongsheng Liu , Kai Yang , Jinbiao Liu , Shiyong Liu , Junzhe Jiang , Liqing Li , Yoshihisa Sakata","doi":"10.1016/j.apcata.2024.120079","DOIUrl":"10.1016/j.apcata.2024.120079","url":null,"abstract":"<div><div>Solar-driven hydrogen production through water splitting is currently one of the research hotspots nowadays. Lanthanum titanate (La<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub>) is one kind of layered-structure perovskite photocatalyst and possesses a superior electronic structure for photocatalytic overall water splitting. However, it suffers from several drawbacks, such as poor photo absorption and easy recombination of photogenerated charge carriers. In this study, sodium (Na) ion-doped La<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub> with plate-like crystal morphology was synthesized by using molten salt synthesis (MSS). The XRD and TEM results indicated that the MSS method enhanced the crystallinity of La<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub>. UV–vis, Raman and EPR spectra disclosed that Na doping through MSS introduced oxygen vacancies. The Na (0.3 mol%)-doped La<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub> (MSS) provided the optimal hydrogen evolution rate, and the value was 6.43 times greater than that of pure La<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub> synthesized by traditional solid-state reaction method. The synergistic effect of crystal facet engineering and defect engineering remarkably enhanced the photocatalytic activity of La<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub>.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"692 ","pages":"Article 120079"},"PeriodicalIF":4.7,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137610","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 : 2024-12-17DOI: 10.1016/j.apcata.2024.120081
Maximilian Medicus, Judith Mettke, Florian Wolke, Johannes Abel, Michael Gallwitz, Erik Reichelt
Chemical industry is facing an upcoming transition from fossil to renewable carbon feedstocks such as CO2. In this context, processes yielding value-added chemicals are of special interest. For the production of higher alcohols (C≥5), iron-based catalysts have been found to be promising. Herein a design of experiment study for the optimization of the space-time yield in dependence of the reaction conditions was conducted for a technically relevant shaped iron-based catalyst optimized for higher alcohol synthesis. In this context also the influence of CO2 on the catalytic performance was studied. In order to allow for an assessment of the catalyst performance in a Power-to-Liquid process, the influence of tail gas recirculation on selectivity and yield was evaluated in a scaled-up test plant. The results presented here provide valuable data for an upcoming techno-economic assessment of the whole Power-to-Liquid process chain.
{"title":"Assessment of process integration of an up-scaled Fischer-Tropsch-catalyst","authors":"Maximilian Medicus, Judith Mettke, Florian Wolke, Johannes Abel, Michael Gallwitz, Erik Reichelt","doi":"10.1016/j.apcata.2024.120081","DOIUrl":"10.1016/j.apcata.2024.120081","url":null,"abstract":"<div><div>Chemical industry is facing an upcoming transition from fossil to renewable carbon feedstocks such as CO<sub>2</sub>. In this context, processes yielding value-added chemicals are of special interest. For the production of higher alcohols (C≥5), iron-based catalysts have been found to be promising. Herein a design of experiment study for the optimization of the space-time yield in dependence of the reaction conditions was conducted for a technically relevant shaped iron-based catalyst optimized for higher alcohol synthesis. In this context also the influence of CO<sub>2</sub> on the catalytic performance was studied. In order to allow for an assessment of the catalyst performance in a Power-to-Liquid process, the influence of tail gas recirculation on selectivity and yield was evaluated in a scaled-up test plant. The results presented here provide valuable data for an upcoming techno-economic assessment of the whole Power-to-Liquid process chain.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"692 ","pages":"Article 120081"},"PeriodicalIF":4.7,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-28DOI: 10.1016/j.apcata.2024.120045
Meng Liu , Caixia Miao , Zhijie Wu
The direct synthesis of methyl acetate (MA) from methanol is an appealing and green approach, but an efficient catalyst is urgently needed. Herein, Cu-Ni bimetallic clusters, with a diameter of ∼1.2 nm, have been successfully encapsulated within BEA zeolite by an in-situ two-step encapsulation method (Cu-Ni@Beta), which significantly favors the dispersion of metals compared to the ion-exchanging (Cu/Ni@Beta) and wet impregnation approach (Cu-Ni/Beta). The as-synthesized Cu-Ni@Beta catalyst shows a MA formation rate of 1.46 mmol s−1 g(Cu+Ni)−1, which is much higher than Cu/Ni@Beta of 0.02 mmol s−1 g(Cu+Ni)−1 and Cu-Ni/Beta of 0.12 mmol s−1 g(Cu+Ni)−1. Characterization studies reveal that zeolite constraints could not only provide the spatial confinement for metal clusters but also induce an electronic interaction between confined Cu and Ni species in Cu-Ni@Beta. This interaction can increase and stabilize Cu+ sites as well as Lewis acid sites, which are crucial for improving catalytic performance. In-situ FTIR experiments indicate that the formation of formaldehyde (CH2O*) is the critical step for methanol to MA, and the CH2O* further couples with methoxy (CH3O*) to form acetate species (CH3CHO*), which subsequently couples with CH3O* to produce MA.
{"title":"Confinement and synergy effect of bimetallic Cu-Ni clusters encapsulated in Beta zeolite for methyl acetate formation from methanol alone","authors":"Meng Liu , Caixia Miao , Zhijie Wu","doi":"10.1016/j.apcata.2024.120045","DOIUrl":"10.1016/j.apcata.2024.120045","url":null,"abstract":"<div><div>The direct synthesis of methyl acetate (MA) from methanol is an appealing and green approach, but an efficient catalyst is urgently needed. Herein, Cu-Ni bimetallic clusters, with a diameter of ∼1.2 nm, have been successfully encapsulated within BEA zeolite by an <em>in-situ</em> two-step encapsulation method (Cu-Ni@Beta), which significantly favors the dispersion of metals compared to the ion-exchanging (Cu/Ni@Beta) and wet impregnation approach (Cu-Ni/Beta). The as-synthesized Cu-Ni@Beta catalyst shows a MA formation rate of 1.46 mmol s<sup>−1</sup> g<sub>(Cu+Ni)</sub><sup>−1</sup>, which is much higher than Cu/Ni@Beta of 0.02 mmol s<sup>−1</sup> g<sub>(Cu+Ni)</sub><sup>−1</sup> and Cu-Ni/Beta of 0.12 mmol s<sup>−1</sup> g<sub>(Cu+Ni)</sub><sup>−1</sup>. Characterization studies reveal that zeolite constraints could not only provide the spatial confinement for metal clusters but also induce an electronic interaction between confined Cu and Ni species in Cu-Ni@Beta. This interaction can increase and stabilize Cu<sup>+</sup> sites as well as Lewis acid sites, which are crucial for improving catalytic performance. <em>In-situ</em> FTIR experiments indicate that the formation of formaldehyde (CH<sub>2</sub>O*) is the critical step for methanol to MA, and the CH<sub>2</sub>O* further couples with methoxy (CH<sub>3</sub>O*) to form acetate species (CH<sub>3</sub>CHO*), which subsequently couples with CH<sub>3</sub>O* to produce MA.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"690 ","pages":"Article 120045"},"PeriodicalIF":4.7,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142744370","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}
This study employed confined-space ZSM-5 zeolite in conjunction with an external magnetic field to manipulate iron oxide phase transformations, thereby enhancing CO2 hydrogenation and the selective production of larger hydrocarbons. Phase transformations of iron oxide were controlled by varying reduction times (0.0–6.0 h) and magnetic flux intensities (0.0–27.7 mT). The FexOy/ZSM-5 zeolite catalyst, at 20.7 mT, exhibited a predominant Fe3O4 phase, achieving the highest CO2 conversion (28.1 %, or 3.3 times higher) and producing 14.4 times more C2–C4 hydrocarbons compared to catalysts without a magnetic field. The combined effects of confined-space ZSM-5 zeolite and the magnetic field simultaneously achieved control over reactant gas diffusion and facilitated formation of Fe3O4 and FeO phases. Olefins, formed via the reverse water-gas shift reaction, underwent chain growth reactions through Fischer-Tropsch synthesis and aromatization within the ZSM-5 zeolite. This approach presents promising opportunities for environmentally friendly CO2 conversion.
{"title":"Promotional effect of external magnetic field in FexOy/ZSM-5 for selective CO2 hydrogenation to C2–C4 and aromatic hydrocarbons","authors":"Ratchanon Chotchaipitakkul , Sirapat Munpollasri , Waleeporn Donphai , Wanwisa Limphirat , Yingyot Poo-arporn , Supinya Nijpanich , Pongsakorn Jantaratana , Thongthai Witoon , Paisan Kongkachuichay , Metta Chareonpanich","doi":"10.1016/j.apcata.2024.120036","DOIUrl":"10.1016/j.apcata.2024.120036","url":null,"abstract":"<div><div>This study employed confined-space ZSM-5 zeolite in conjunction with an external magnetic field to manipulate iron oxide phase transformations, thereby enhancing CO<sub>2</sub> hydrogenation and the selective production of larger hydrocarbons. Phase transformations of iron oxide were controlled by varying reduction times (0.0–6.0 h) and magnetic flux intensities (0.0–27.7 mT). The Fe<sub>x</sub>O<sub>y</sub>/ZSM-5 zeolite catalyst, at 20.7 mT, exhibited a predominant Fe<sub>3</sub>O<sub>4</sub> phase, achieving the highest CO<sub>2</sub> conversion (28.1 %, or 3.3 times higher) and producing 14.4 times more C<sub>2</sub>–C<sub>4</sub> hydrocarbons compared to catalysts without a magnetic field. The combined effects of confined-space ZSM-5 zeolite and the magnetic field simultaneously achieved control over reactant gas diffusion and facilitated formation of Fe<sub>3</sub>O<sub>4</sub> and FeO phases. Olefins, formed via the reverse water-gas shift reaction, underwent chain growth reactions through Fischer-Tropsch synthesis and aromatization within the ZSM-5 zeolite. This approach presents promising opportunities for environmentally friendly CO<sub>2</sub> conversion.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"690 ","pages":"Article 120036"},"PeriodicalIF":4.7,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142744371","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 : 2024-11-26DOI: 10.1016/j.apcata.2024.120044
Chunyan Deng , Qun Li , Wanting Huang , Dong Xia , Peng Huang , Ruifang Lu , Luxi Tan , Lichun Dong
Co-based catalysts exhibit considerable catalytic activity in oxidative reactions, yet challenges remain in synthesizing Co3O4 materials featuring both large surface area and high activity. Here, ultrathin La0.029CoOx nanosheets were post-treated with various concentrations of dilute nitric acid to obtain the two-dimensionally geometric Co3O4-H nanosheets catalysts. Among them, the resultant Co3O4-0.1H catalyst disclosed significantly enhanced catalytic activity, enabling to achieve 100 % conversion of benzene at 230 °C under an ultrahigh weight hourly space velocity (WHSV) of 60,000 mL·g−1·h−1. Additionally, the catalyst also displayed excellent catalytic durability and well catalytic stability over 5 cyclic tests and 45 h of long-period operation. A thorough characterization results revealed that the superior catalytic performance of Co3O4-0.1H was attributed to its distinct nanosheet morphology, high specific surface area and abundant surface defect sites. This work highlights the effectiveness and simplicity of acid washing treatment strategy in improving the catalytic oxidation activity of transition metal oxide catalysts.
{"title":"Acid washing-assisted synthesis of porous Co3O4 nanosheet catalyst featuring efficient benzene oxidation performance","authors":"Chunyan Deng , Qun Li , Wanting Huang , Dong Xia , Peng Huang , Ruifang Lu , Luxi Tan , Lichun Dong","doi":"10.1016/j.apcata.2024.120044","DOIUrl":"10.1016/j.apcata.2024.120044","url":null,"abstract":"<div><div>Co-based catalysts exhibit considerable catalytic activity in oxidative reactions, yet challenges remain in synthesizing Co<sub>3</sub>O<sub>4</sub> materials featuring both large surface area and high activity. Here, ultrathin La<sub>0.029</sub>CoO<sub>x</sub> nanosheets were post-treated with various concentrations of dilute nitric acid to obtain the two-dimensionally geometric Co<sub>3</sub>O<sub>4</sub>-H nanosheets catalysts. Among them, the resultant Co<sub>3</sub>O<sub>4</sub>-0.1H catalyst disclosed significantly enhanced catalytic activity, enabling to achieve 100 % conversion of benzene at 230 °C under an ultrahigh weight hourly space velocity (WHSV) of 60,000 mL·g<sup>−1</sup>·h<sup>−1</sup>. Additionally, the catalyst also displayed excellent catalytic durability and well catalytic stability over 5 cyclic tests and 45 h of long-period operation. A thorough characterization results revealed that the superior catalytic performance of Co<sub>3</sub>O<sub>4</sub>-0.1H was attributed to its distinct nanosheet morphology, high specific surface area and abundant surface defect sites. This work highlights the effectiveness and simplicity of acid washing treatment strategy in improving the catalytic oxidation activity of transition metal oxide catalysts.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"690 ","pages":"Article 120044"},"PeriodicalIF":4.7,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142744369","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 : 2024-11-26DOI: 10.1016/j.apcata.2024.120035
Fedor S. Golub , Quanjun Xiang , Dmitri A. Bulushev
Covalent triazine frameworks (CTFs) are relatively novel materials and could be used as supports for single-atom metal catalysts (SACs), which attract a lot of interest during last years. The present review shows that CTFs are suitable supports for SACs for different reactions including oxidation, hydroformylation, O2 reduction, N2 fixation, CO2 photoreduction, hydrogen production, transfer and evolution. It discusses synthesis techniques and focuses on the structure of the obtained single-atom active sites including Pd, Ir, Ru, Rh, Pt, Ni, Co, Cu, and Fe atoms. It also considers some mechanisms of the mentioned reactions. The critical challenges and future perspectives for SACs based on CTFs are considered. This knowledge could be used as a base for design and engineering of single-atom active sites and will allow one to develop novel catalysts for different catalytic processes.
共价三嗪框架（CTFs）是一种新型材料，可以作为单原子金属催化剂（SACs）的载体，近年来引起了人们的广泛关注。研究表明，CTFs是SACs在氧化、氢甲酰化、O2还原、N2固定、CO2光还原、产氢、转移和进化等不同反应中的合适载体。它讨论了合成技术，并重点讨论了获得的单原子活性位点的结构，包括Pd， Ir, Ru, Rh, Pt, Ni, Co， Cu和Fe原子。本文还讨论了上述反应的一些机理。考虑了基于CTFs的sac的关键挑战和未来前景。这些知识可以作为单原子活性位点设计和工程的基础，并将允许人们为不同的催化过程开发新的催化剂。
{"title":"Single-atom catalysts supported on covalent triazine frameworks","authors":"Fedor S. Golub , Quanjun Xiang , Dmitri A. Bulushev","doi":"10.1016/j.apcata.2024.120035","DOIUrl":"10.1016/j.apcata.2024.120035","url":null,"abstract":"<div><div>Covalent triazine frameworks (CTFs) are relatively novel materials and could be used as supports for single-atom metal catalysts (SACs), which attract a lot of interest during last years. The present review shows that CTFs are suitable supports for SACs for different reactions including oxidation, hydroformylation, O<sub>2</sub> reduction, N<sub>2</sub> fixation, CO<sub>2</sub> photoreduction, hydrogen production, transfer and evolution. It discusses synthesis techniques and focuses on the structure of the obtained single-atom active sites including Pd, Ir, Ru, Rh, Pt, Ni, Co, Cu, and Fe atoms. It also considers some mechanisms of the mentioned reactions. The critical challenges and future perspectives for SACs based on CTFs are considered. This knowledge could be used as a base for design and engineering of single-atom active sites and will allow one to develop novel catalysts for different catalytic processes.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"690 ","pages":"Article 120035"},"PeriodicalIF":4.7,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745132","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 : 2024-11-19DOI: 10.1016/j.apcata.2024.120031
Yi Yuan , Xiaozhou Chen , Longbin Deng , Shuaishuai Zhou , Congzhen Qiao , Zhenheng Diao , Hongyan Wang , Yajie Tian
In this study, a catalyst comprising Ru-Zr bimetals supported on core-shell ZSM-5 zeolite is tailored for catalytic conversion of furfural to yield γ-valerolactone via promoted two-step cascade reaction. ZrO2 encapsulated within hierarchical ZSM-5 zeolite is synthesized via a one-pot hydrothermal method, followed by sequential treatment with NaOH to yield Zr@ZSM-OH. Subsequently, the RuO2 component is introduced through impregnation, followed by calcination to obtain Ru-Zr@ZSM-OH. In conversion of furfural, the synergistic effect of highly dispersed ZrO2 acting as Lewis acid sites, combined with Brønsted acid sites provided by zeolite, facilitates the production of isopropyl levulinate via catalytic hydrogenation transfer, under either H2 or N2 atmosphere. In the secondary step, the introduced RuO2 promotes the adsorption and spillover of active H2, thereby accelerating the conversion of isopropyl levulinate to γ-valerolactone. The as-synthesized Ru-Zr@ZSM-OH catalyst achieves an impressive yield of 92.6 wt% of γ-valerolactone after just a 2 h reaction at 175 °C.
{"title":"Production of γ-valerolactone from furfural by core-shell ZSM-5 supporting Ru-Zr bimetals through enhanced cascade reaction","authors":"Yi Yuan , Xiaozhou Chen , Longbin Deng , Shuaishuai Zhou , Congzhen Qiao , Zhenheng Diao , Hongyan Wang , Yajie Tian","doi":"10.1016/j.apcata.2024.120031","DOIUrl":"10.1016/j.apcata.2024.120031","url":null,"abstract":"<div><div>In this study, a catalyst comprising Ru-Zr bimetals supported on core-shell ZSM-5 zeolite is tailored for catalytic conversion of furfural to yield γ-valerolactone via promoted two-step cascade reaction. ZrO<sub>2</sub> encapsulated within hierarchical ZSM-5 zeolite is synthesized via a one-pot hydrothermal method, followed by sequential treatment with NaOH to yield Zr@ZSM-OH. Subsequently, the RuO<sub>2</sub> component is introduced through impregnation, followed by calcination to obtain Ru-Zr@ZSM-OH. In conversion of furfural, the synergistic effect of highly dispersed ZrO<sub>2</sub> acting as Lewis acid sites, combined with Brønsted acid sites provided by zeolite, facilitates the production of isopropyl levulinate via catalytic hydrogenation transfer, under either H<sub>2</sub> or N<sub>2</sub> atmosphere. In the secondary step, the introduced RuO<sub>2</sub> promotes the adsorption and spillover of active H<sub>2</sub>, thereby accelerating the conversion of isopropyl levulinate to γ-valerolactone. The as-synthesized Ru-Zr@ZSM-OH catalyst achieves an impressive yield of 92.6 wt% of γ-valerolactone after just a 2 h reaction at 175 °C.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"690 ","pages":"Article 120031"},"PeriodicalIF":4.7,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142703789","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 : 2024-11-19DOI: 10.1016/j.apcata.2024.120029
Chonghao Chen , Zixin Song , Dianhua Liu
Carbon dioxide (CO2) hydrogenation to aromatics is promising for reducing the burden of petroleum fuels. Herein, iron-based catalyst was mixed with boron modified HZSM-5 with pre-treatment and post-treatment method. The textural, acidic and element distribution properties over zeolite framework and external surface were studied. Combining with characterizations for internal and external coke, the element distribution-acidity-coke-stability relationship over boron-modified zeolite was put forward. Pre-treated zeolite witnessed reduced amount of external and total Brönsted acid sites (BAS) with similar degree, and increase paired Al (Alpair) fraction in the intersection site, leading to increased aromatics selectivity and reduced coke amount. While boron post-treatment significantly reduced external surface BAS and inhibited formation of condensed external coke. Afterwards, the mechanism of olefins aromatization was studied and found that PT-Z5-B greatly suppressed the overalkylation of light aromatics, thus alleviating the co-deactivation pattern generated by transformation of coke precursors from zeolite to iron-based catalyst.
{"title":"Insight into the coke alleviation pattern over iron-based and boron-modified HZSM-5 bifunctional catalyst for direct CO2 hydrogenation to aromatics","authors":"Chonghao Chen , Zixin Song , Dianhua Liu","doi":"10.1016/j.apcata.2024.120029","DOIUrl":"10.1016/j.apcata.2024.120029","url":null,"abstract":"<div><div>Carbon dioxide (CO<sub>2</sub>) hydrogenation to aromatics is promising for reducing the burden of petroleum fuels. Herein, iron-based catalyst was mixed with boron modified HZSM-5 with pre-treatment and post-treatment method. The textural, acidic and element distribution properties over zeolite framework and external surface were studied. Combining with characterizations for internal and external coke, the element distribution-acidity-coke-stability relationship over boron-modified zeolite was put forward. Pre-treated zeolite witnessed reduced amount of external and total Brönsted acid sites (BAS) with similar degree, and increase paired Al (Al<sub>pair</sub>) fraction in the intersection site, leading to increased aromatics selectivity and reduced coke amount. While boron post-treatment significantly reduced external surface BAS and inhibited formation of condensed external coke. Afterwards, the mechanism of olefins aromatization was studied and found that PT-Z5-B greatly suppressed the overalkylation of light aromatics, thus alleviating the co-deactivation pattern generated by transformation of coke precursors from zeolite to iron-based catalyst.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"689 ","pages":"Article 120029"},"PeriodicalIF":4.7,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702561","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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