Water oxidation is a multielectron complex reaction that produces molecular oxygen as the final product. The article addresses the lack of confirmation of oxygen product formation in electrochemical oxygen evolution reaction (OER) studies, despite the extensive research conducted on catalysts for water splitting. It critically evaluates the trend observed in many studies that solely rely on electrochemical methods for OER quantification without confirming the oxygen product via complementary analytical techniques. The omission of measuring evolved oxygen gas leaves a crucial gap in the quantification of the OER process and raises concerns about the validity and accuracy of reported results. Analytical techniques, such as gas chromatography, Rotating Ring-Disk Electrode (RRDE), fluorescence oxygen probes, Clark electrode, and volumetry are critically analyzed and described to ensure the reliability and credibility of voltammetry and bulk electrolysis to provide a more accurate assessment of the OER process.
水氧化是一种多电子复合反应，其最终产物是分子氧。尽管对水分离催化剂进行了广泛的研究，但在电化学氧进化反应（OER）研究中缺乏对氧产物形成的确认。文章对许多研究中观察到的趋势进行了批判性评估，这些研究仅仅依靠电化学方法对 OER 进行定量，而没有通过补充分析技术对氧产物进行确认。由于没有测量挥发的氧气，因此在定量 OER 过程中留下了关键的空白，并引发了对所报告结果的有效性和准确性的担忧。本文对气相色谱法、旋转环盘电极 (RRDE)、荧光氧探针、克拉克电极和容量测定法等分析技术进行了批判性分析和描述，以确保伏安法和散装电解法的可靠性和可信度，从而为 OER 过程提供更准确的评估。
{"title":"Measurements of Dioxygen Formation in Catalytic Electrochemical Water Splitting","authors":"C. Tiwari, Y. Geletii","doi":"10.3390/catal14010013","DOIUrl":"https://doi.org/10.3390/catal14010013","url":null,"abstract":"Water oxidation is a multielectron complex reaction that produces molecular oxygen as the final product. The article addresses the lack of confirmation of oxygen product formation in electrochemical oxygen evolution reaction (OER) studies, despite the extensive research conducted on catalysts for water splitting. It critically evaluates the trend observed in many studies that solely rely on electrochemical methods for OER quantification without confirming the oxygen product via complementary analytical techniques. The omission of measuring evolved oxygen gas leaves a crucial gap in the quantification of the OER process and raises concerns about the validity and accuracy of reported results. Analytical techniques, such as gas chromatography, Rotating Ring-Disk Electrode (RRDE), fluorescence oxygen probes, Clark electrode, and volumetry are critically analyzed and described to ensure the reliability and credibility of voltammetry and bulk electrolysis to provide a more accurate assessment of the OER process.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":"3 12","pages":""},"PeriodicalIF":3.9,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138944215","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}
Ca2Fe2O5-based catalysts were synthesized from siderite and calcite precursors, which were processed in the form of pelletized samples and tested as water gas shift catalysts. Catalytic tests were performed in a tubular reactor, at temperatures in the range 400–500 °C and with different H2O:CO ratios, diluted with N2; this demonstrates the positive impact of Ca2Fe2O5 on conversion of CO and H2 yield, relative to corresponding tests without catalyst. The catalytic performance was also remarkably boosted in a microwave-heated reactor, relative to conventional electric heating. Post-mortem analysis of spent catalysts showed significant XRD reflections of spinel phases (Fe3O4 and CaFe2O4), and SiO2 from the siderite precursor. Traces of calcium carbonate were also identified, and FTIR analysis revealed relevant bands ascribed to calcium carbonate and adsorbed CO2. Thermodynamic modelling was performed to assess the redox tolerance of Ca2Fe2O5-based catalysts in conditions expected for gasification of biomass and thermochemical conditions at somewhat lower temperatures (≤500 °C), as a guideline for suitable conditions for water gas shift. This modelling, combined with the results of catalytic tests and post-mortem analysis of spent catalysts, indicated that the O2 and CO2 storage ability of Ca2Fe2O5 contributes to its catalytic activity, suggesting prospects to enhance the H2 content of producer gases by water gas shift.
{"title":"Ca2Fe2O5-Based WGS Catalysts to Enhance the H2 Yield of Producer Gases","authors":"I. Antunes, L. Ruivo, L. Tarelho, Jorge R. Frade","doi":"10.3390/catal14010012","DOIUrl":"https://doi.org/10.3390/catal14010012","url":null,"abstract":"Ca2Fe2O5-based catalysts were synthesized from siderite and calcite precursors, which were processed in the form of pelletized samples and tested as water gas shift catalysts. Catalytic tests were performed in a tubular reactor, at temperatures in the range 400–500 °C and with different H2O:CO ratios, diluted with N2; this demonstrates the positive impact of Ca2Fe2O5 on conversion of CO and H2 yield, relative to corresponding tests without catalyst. The catalytic performance was also remarkably boosted in a microwave-heated reactor, relative to conventional electric heating. Post-mortem analysis of spent catalysts showed significant XRD reflections of spinel phases (Fe3O4 and CaFe2O4), and SiO2 from the siderite precursor. Traces of calcium carbonate were also identified, and FTIR analysis revealed relevant bands ascribed to calcium carbonate and adsorbed CO2. Thermodynamic modelling was performed to assess the redox tolerance of Ca2Fe2O5-based catalysts in conditions expected for gasification of biomass and thermochemical conditions at somewhat lower temperatures (≤500 °C), as a guideline for suitable conditions for water gas shift. This modelling, combined with the results of catalytic tests and post-mortem analysis of spent catalysts, indicated that the O2 and CO2 storage ability of Ca2Fe2O5 contributes to its catalytic activity, suggesting prospects to enhance the H2 content of producer gases by water gas shift.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":"38 20","pages":""},"PeriodicalIF":3.9,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138948789","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 the presented work, the catalytic performance of a nickel catalyst, in CO2 hydrogenation to methane, within a ZrO2 open-cell foam (OCF)-based catalyst was studied. Two series of analogous samples were prepared and coated with 100–150 mg of a Mg-Al oxide interface to stabilize the formation of well-dispersed Ni crystallites, with 10–15 wt% of nickel as an active phase, based on 30 ppi foam or 45 ppi foam. The main factor influencing catalytic performance was the geometric parameters of the applied foams. The series of catalysts based on 30 ppi OCF showed CO2 conversion in the range of 30–50% at 300 °C, while those based on 45 ppi OCF resulted in a significantly enhancement of the catalytic activity: 90–92% CO2 conversion under the same experimental conditions. Calculations of the internal and external mass transfer limitations were performed. The observed difference in the catalytic activity was primarily related to the radial transport inside the pores, confirmed with the explicitly higher conversions.
本文研究了一种镍催化剂在基于 ZrO2 的开孔泡沫 (OCF) 催化剂中将二氧化碳加氢转化为甲烷的催化性能。在 30 ppi 泡沫或 45 ppi 泡沫的基础上，制备了两个系列的类似样品，并在其表面涂覆了 100-150 毫克的氧化镁-氧化铝界面，以稳定形成分散良好的镍晶体，其中 10-15 wt%的镍为活性相。影响催化性能的主要因素是所用泡沫的几何参数。基于 30 ppi OCF 的系列催化剂在 300 °C 时的二氧化碳转化率为 30-50%，而基于 45 ppi OCF 的催化剂则显著提高了催化活性：在相同的实验条件下，二氧化碳转化率为 90-92%。对内部和外部传质限制进行了计算。所观察到的催化活性差异主要与孔隙内的径向传输有关，这一点通过更高的转化率得到了证实。
{"title":"Optimization of an Open-Cell Foam-Based Ni-Mg-Al Catalyst for Enhanced CO2 Hydrogenation to Methane","authors":"Paulina Summa, M. Motak, P. Da Costa","doi":"10.3390/catal14010011","DOIUrl":"https://doi.org/10.3390/catal14010011","url":null,"abstract":"In the presented work, the catalytic performance of a nickel catalyst, in CO2 hydrogenation to methane, within a ZrO2 open-cell foam (OCF)-based catalyst was studied. Two series of analogous samples were prepared and coated with 100–150 mg of a Mg-Al oxide interface to stabilize the formation of well-dispersed Ni crystallites, with 10–15 wt% of nickel as an active phase, based on 30 ppi foam or 45 ppi foam. The main factor influencing catalytic performance was the geometric parameters of the applied foams. The series of catalysts based on 30 ppi OCF showed CO2 conversion in the range of 30–50% at 300 °C, while those based on 45 ppi OCF resulted in a significantly enhancement of the catalytic activity: 90–92% CO2 conversion under the same experimental conditions. Calculations of the internal and external mass transfer limitations were performed. The observed difference in the catalytic activity was primarily related to the radial transport inside the pores, confirmed with the explicitly higher conversions.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":"5 11","pages":""},"PeriodicalIF":3.9,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138952134","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}
Cu-SSZ-39 zeolite with an AEI structure exhibits excellent hydrothermal stability and can be a potential alternative to Cu-SSZ-13 zeolite SCR catalysts for NOx removal in diesel vehicles. However, the inferior low-temperature performance of Cu-SSZ-39 leads to substantial NOx emissions during the cold-start period, impeding its practical application. In this study, Ce-Mn oxide-modified Cu-SSZ-39 catalysts (CeMnOx/Cu-SSZ-39) and references (CeO2/Cu-SSZ-39 and MnOx/Cu-SSZ-39) were prepared by the ion-exchange of Cu ions followed by impregnation of the oxide precursors, with the aim of enhancing the NH3-SCR performance at low temperatures. The modified catalysts exhibited improved low-temperature activity and hydrothermal stability compared to the unmodified counterpart. In particular, CeMnOx/Cu-SSZ-39 showed the highest activity among the three catalysts and achieved NOx conversions above 90% within the temperature range of 180 °C to 600 °C, even after undergoing hydrothermal aging at 800 °C. Experimental results indicated that the synergistic effect between Ce and Mn in CeMnOx improves the redox properties and acidity of the catalyst due to the presence of Ce3+, Mn4+, and abundant adsorbed oxygen species, which facilitate low-temperature SCR reactions. Furthermore, the interaction of CeMnOx with Cu-SSZ-39 stabilizes the zeolite framework and hinders the agglomeration of Cu species during the hydrothermal aging process, contributing to its exceptional hydrothermal stability. The kinetics and NO oxidation experiments demonstrated that CeMnOx provides access to fast SCR reaction pathways by oxidizing NO to NO2, resulting in a significant increase in low-temperature activity. This study provides novel guidelines for the design and preparation of Cu-SSZ-39 zeolite with outstanding SCR performance over a wide temperature range.
具有 AEI 结构的 Cu-SSZ-39 沸石具有出色的水热稳定性，可以替代 Cu-SSZ-13 沸石 SCR 催化剂，用于去除柴油车中的氮氧化物。然而，Cu-SSZ-39 的低温性能较差，导致其在冷启动期间排放大量氮氧化物，阻碍了其实际应用。本研究通过离子交换铜离子，然后浸渍氧化物前驱体，制备了铈锰氧化物改性的 Cu-SSZ-39 催化剂（CeMnOx/Cu-SSZ-39）和参照物（CeO2/Cu-SSZ-39 和 MnOx/Cu-SSZ-39），旨在提高低温下的 NH3-SCR 性能。与未改性的催化剂相比，改性催化剂具有更高的低温活性和水热稳定性。其中，CeMnOx/Cu-SSZ-39 在三种催化剂中表现出最高的活性，在 180 °C 至 600 °C 的温度范围内，即使经过 800 °C 的水热老化，其氮氧化物转化率也能达到 90% 以上。实验结果表明，CeMnOx 中 Ce 和 Mn 的协同作用改善了催化剂的氧化还原特性和酸性，这是因为 Ce3+、Mn4+ 和丰富的吸附氧物种的存在促进了低温 SCR 反应的进行。此外，CeMnOx 与 Cu-SSZ-39 的相互作用稳定了沸石框架，阻碍了水热老化过程中 Cu 物种的团聚，使其具有优异的水热稳定性。动力学和 NO 氧化实验表明，CeMnOx 通过将 NO 氧化为 NO2，提供了快速 SCR 反应途径，从而显著提高了低温活性。这项研究为设计和制备在宽温度范围内具有出色 SCR 性能的 Cu-SSZ-39 沸石提供了新的指导。
{"title":"Enhanced Low-Temperature Activity and Hydrothermal Stability of Ce-Mn Oxide-Modified Cu-SSZ-39 Catalysts for NH3-SCR of NOx","authors":"Ahui Tang, Fuzhen Yang, Ying Xin, Xiaoli Zhu, Long Yu, Shuai Liu, Dongxu Han, Junxiu Jia, Yaning Lu, Zhenguo Li, Zhaoliang Zhang","doi":"10.3390/catal14010010","DOIUrl":"https://doi.org/10.3390/catal14010010","url":null,"abstract":"Cu-SSZ-39 zeolite with an AEI structure exhibits excellent hydrothermal stability and can be a potential alternative to Cu-SSZ-13 zeolite SCR catalysts for NOx removal in diesel vehicles. However, the inferior low-temperature performance of Cu-SSZ-39 leads to substantial NOx emissions during the cold-start period, impeding its practical application. In this study, Ce-Mn oxide-modified Cu-SSZ-39 catalysts (CeMnOx/Cu-SSZ-39) and references (CeO2/Cu-SSZ-39 and MnOx/Cu-SSZ-39) were prepared by the ion-exchange of Cu ions followed by impregnation of the oxide precursors, with the aim of enhancing the NH3-SCR performance at low temperatures. The modified catalysts exhibited improved low-temperature activity and hydrothermal stability compared to the unmodified counterpart. In particular, CeMnOx/Cu-SSZ-39 showed the highest activity among the three catalysts and achieved NOx conversions above 90% within the temperature range of 180 °C to 600 °C, even after undergoing hydrothermal aging at 800 °C. Experimental results indicated that the synergistic effect between Ce and Mn in CeMnOx improves the redox properties and acidity of the catalyst due to the presence of Ce3+, Mn4+, and abundant adsorbed oxygen species, which facilitate low-temperature SCR reactions. Furthermore, the interaction of CeMnOx with Cu-SSZ-39 stabilizes the zeolite framework and hinders the agglomeration of Cu species during the hydrothermal aging process, contributing to its exceptional hydrothermal stability. The kinetics and NO oxidation experiments demonstrated that CeMnOx provides access to fast SCR reaction pathways by oxidizing NO to NO2, resulting in a significant increase in low-temperature activity. This study provides novel guidelines for the design and preparation of Cu-SSZ-39 zeolite with outstanding SCR performance over a wide temperature range.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":"38 25","pages":""},"PeriodicalIF":3.9,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138950154","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}
Converting superfluous CO2 into value-added chemicals is regarded as a practical approach for alleviating the global warming problem. Powered by renewable electricity, CO2 reduction reactions (CO2RR) have attracted intense interest owing to their favorable efficiency. Metal catalysts exhibit high catalytic efficiency for CO2 reduction. However, the reaction mechanisms have yet to be investigated. In this study, CO2RR to CH3OH catalyzed by CuAg bimetal is theoretically investigated. The configurations and stability of the catalysts and the reaction pathway are studied. The results unveil the mechanisms of the catalysis process and prove the feasibility of CuAg clusters as efficient CO2RR catalysts, serving as guidance for further experimental exploration. This study provides guidance and a reference for future work in the design of mixed-metal catalysts with high CO2RR performance.
{"title":"Density Functional Theory Study of CuAg Bimetal Electrocatalyst for CO2RR to Produce CH3OH","authors":"Sensen Xue, Xingyou Liang, Qing Zhang, Xuefeng Ren, Liguo Gao, Tingli Ma, Anmin Liu","doi":"10.3390/catal14010007","DOIUrl":"https://doi.org/10.3390/catal14010007","url":null,"abstract":"Converting superfluous CO2 into value-added chemicals is regarded as a practical approach for alleviating the global warming problem. Powered by renewable electricity, CO2 reduction reactions (CO2RR) have attracted intense interest owing to their favorable efficiency. Metal catalysts exhibit high catalytic efficiency for CO2 reduction. However, the reaction mechanisms have yet to be investigated. In this study, CO2RR to CH3OH catalyzed by CuAg bimetal is theoretically investigated. The configurations and stability of the catalysts and the reaction pathway are studied. The results unveil the mechanisms of the catalysis process and prove the feasibility of CuAg clusters as efficient CO2RR catalysts, serving as guidance for further experimental exploration. This study provides guidance and a reference for future work in the design of mixed-metal catalysts with high CO2RR performance.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":"33 7","pages":""},"PeriodicalIF":3.9,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138954637","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}
Catalysts play a pivotal role in modern industries, such as energy, pharmaceuticals, and petrochemicals, serving as cornerstone of high-tech production. Noble metals, such as gold, silver, and platinum group elements, possess the superb catalytic characteristics of high-temperature oxidation resistance, corrosion resistance, stable electrochemical performance, high catalytic activity, and so on. These characteristics offer excellent prospects for applications in catalysis. In this review, we summarize innovative approaches to regulating the size and morphology of nano-noble metal catalysts with different dimensions. We also showcase typical prominent examples of their applications in exhaust gas purification, battery manufacturing, water splitting, and selective hydrogenation. Finally, perspectives are discussed in terms of future research opportunities in the realm of noble metal nanocatalysts.
{"title":"Dimension Engineering in Noble-Metal-Based Nanocatalysts","authors":"Bei Liu, Haosen Yang, Pengfei Hu, Guangsheng Wang, Yongqiang Guo, Hewei Zhao","doi":"10.3390/catal14010009","DOIUrl":"https://doi.org/10.3390/catal14010009","url":null,"abstract":"Catalysts play a pivotal role in modern industries, such as energy, pharmaceuticals, and petrochemicals, serving as cornerstone of high-tech production. Noble metals, such as gold, silver, and platinum group elements, possess the superb catalytic characteristics of high-temperature oxidation resistance, corrosion resistance, stable electrochemical performance, high catalytic activity, and so on. These characteristics offer excellent prospects for applications in catalysis. In this review, we summarize innovative approaches to regulating the size and morphology of nano-noble metal catalysts with different dimensions. We also showcase typical prominent examples of their applications in exhaust gas purification, battery manufacturing, water splitting, and selective hydrogenation. Finally, perspectives are discussed in terms of future research opportunities in the realm of noble metal nanocatalysts.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":"17 14","pages":""},"PeriodicalIF":3.9,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139168972","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}
Qingwei Zhou, Mingjiao Shi, Mengfan Wu, Ningbin Zhao, Peizheng Shi, Yangguang Zhu, Aiwu Wang, Chen Ye, Cheng-Te Lin, Li Fu
This review critically evaluates the recent advancements in graphene dopants for electrocatalytic quantification of small molecules and ions. Emphasizing the enhanced catalytic activity and specificity of doped graphene, the paper delves into the various doping methods, ranging from chemical to physical techniques. It presents a detailed analysis of the mechanisms underlying graphene-based electrocatalysis and its applications in environmental monitoring, health care, and pharmaceuticals. The review also addresses challenges such as the reproducibility and stability of doped graphene, suggesting future research directions. By summarizing the latest findings, this review aims to elucidate the role of doped graphene in improving the sensitivity and selectivity of electrocatalytic processes, bridging the gap between research and practical use.
{"title":"Optimizing Graphene Dopants for Direct Electrocatalytic Quantification of Small Molecules and Ions","authors":"Qingwei Zhou, Mingjiao Shi, Mengfan Wu, Ningbin Zhao, Peizheng Shi, Yangguang Zhu, Aiwu Wang, Chen Ye, Cheng-Te Lin, Li Fu","doi":"10.3390/catal14010008","DOIUrl":"https://doi.org/10.3390/catal14010008","url":null,"abstract":"This review critically evaluates the recent advancements in graphene dopants for electrocatalytic quantification of small molecules and ions. Emphasizing the enhanced catalytic activity and specificity of doped graphene, the paper delves into the various doping methods, ranging from chemical to physical techniques. It presents a detailed analysis of the mechanisms underlying graphene-based electrocatalysis and its applications in environmental monitoring, health care, and pharmaceuticals. The review also addresses challenges such as the reproducibility and stability of doped graphene, suggesting future research directions. By summarizing the latest findings, this review aims to elucidate the role of doped graphene in improving the sensitivity and selectivity of electrocatalytic processes, bridging the gap between research and practical use.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":"120 44","pages":""},"PeriodicalIF":3.9,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138953970","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}
Anup Paul, Ismayil M. Garazade, Anirban Karmakar, R. A. Khan, M. F. C. Guedes da Silva, Ana V M Nunes, A. Pombeiro
In this study, we report the design, synthesis, and catalytic application of the novel nitrogen-rich Zn(II) MOF [Zn2(μ3-1κN,2κN′,3κO-HL)2(DMF)2]n·nH2O (HL2− = 4-((4-(1H-tetrazol-5-yl)phenyl)carbamoyl)benzoate), denoted as ZnMOF, for the efficient conversion of carbon dioxide (CO2) to cyclic carbonates via cycloaddition with epoxides. It was synthesised from a tetrazole appended amide-functionalised pro-ligand (H3L) and Zn(NO3)2·6H2O under hydrothermal conditions. The synthesised material was characterised namely by elemental analysis, infrared spectroscopy, powder X-ray diffraction (PXRD), and single-crystal X-ray diffraction analyses. The catalytic potential of ZnMOF was investigated in the CO2 cycloaddition reaction with various epoxides, with conversions ranging from 17% to 99%. The catalyst retained its activity across multiple reaction cycles, demonstrating its stability and reusability. The influence of co-catalysts on the reaction was explored, with tetrabutylammonium bromide (TBABr) emerging as the most effective one. A plausible reaction mechanism is proposed.
在本研究中，我们报告了新型富氮 Zn(II) MOF [Zn2(μ3-1κN,2κN′、3κO-HL）2（DMF）2]n-nH2O（HL2- = 4-((4-(1H-四唑-5-基)苯基)氨基甲酰基)苯甲酸酯），简称 ZnMOF，用于通过与环氧化物的环加成将二氧化碳（CO2）高效转化为环碳酸盐。它是在水热条件下，由添加了酰胺功能化原配体（H3L）的四唑和 Zn(NO3)2-6H2O 合成的。合成材料的表征包括元素分析、红外光谱、粉末 X 射线衍射 (PXRD) 和单晶 X 射线衍射分析。在与各种环氧化物进行 CO2 环加成反应时，研究了 ZnMOF 的催化潜能，其转化率从 17% 到 99%。该催化剂在多个反应循环中均保持活性，证明了其稳定性和可重复使用性。研究还探讨了助催化剂对反应的影响，发现四丁基溴化铵（TBABr）是最有效的助催化剂。提出了一种合理的反应机制。
{"title":"Nitrogen-Rich Tetrazole–Amide-Functionalised Zn Metal–Organic Framework as Catalyst for Efficient Catalytic CO2 Cycloaddition with Epoxides","authors":"Anup Paul, Ismayil M. Garazade, Anirban Karmakar, R. A. Khan, M. F. C. Guedes da Silva, Ana V M Nunes, A. Pombeiro","doi":"10.3390/catal14010006","DOIUrl":"https://doi.org/10.3390/catal14010006","url":null,"abstract":"In this study, we report the design, synthesis, and catalytic application of the novel nitrogen-rich Zn(II) MOF [Zn2(μ3-1κN,2κN′,3κO-HL)2(DMF)2]n·nH2O (HL2− = 4-((4-(1H-tetrazol-5-yl)phenyl)carbamoyl)benzoate), denoted as ZnMOF, for the efficient conversion of carbon dioxide (CO2) to cyclic carbonates via cycloaddition with epoxides. It was synthesised from a tetrazole appended amide-functionalised pro-ligand (H3L) and Zn(NO3)2·6H2O under hydrothermal conditions. The synthesised material was characterised namely by elemental analysis, infrared spectroscopy, powder X-ray diffraction (PXRD), and single-crystal X-ray diffraction analyses. The catalytic potential of ZnMOF was investigated in the CO2 cycloaddition reaction with various epoxides, with conversions ranging from 17% to 99%. The catalyst retained its activity across multiple reaction cycles, demonstrating its stability and reusability. The influence of co-catalysts on the reaction was explored, with tetrabutylammonium bromide (TBABr) emerging as the most effective one. A plausible reaction mechanism is proposed.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":"91 11","pages":""},"PeriodicalIF":3.9,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138954379","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}
I. Kuźniarska-Biernacka, Inês Ferreira, Marta Monteiro, A. C. Santos, Bruno Valentim, Alexandra Guedes, João H. Belo, João P. Araújo, Cristina Freire, A. F. Peixoto
4-nitrophenol (4-NPh) is a harmful compound produced in large amounts in the chemical industry, and its reduction to aminophenol (4-APh) using noble metals as catalysts is one of the most studied processes. The development of noble metal-free catalysts represents an economic advantage in large-scale applications and contributes to the sustainability of raw materials. Coal fly ash (FA), a major waste stream from coal combustion, contains an easily recoverable magnetic fraction (FAmag sample) composed of Fe-rich particles that could substitute noble metal catalysts in 4-NPh reduction, with the concomitant advantage of being easily recovered via magnetic separation. For this purpose, a new composite material containing copper ferrite nanoparticles (FAmag@CS@CuFe) was prepared via a facile, environmentally friendly and cost-effective method based on three components: FAmag as the core, a biobased polymer chitosan (CS) as the linker and copper ferrite CuFe2O4 nanoparticles (CuFe) as the active sites. The structure, morphology, composition and magnetic properties of the FAmag@CS@CuFe material were studied to assess the efficiency of the preparation. It was found that the biopolymer prevented the aggregation of CuFe nanoparticles and enabled a synergistically outstanding activity towards the reduction of 4-NPh in comparison to the pristine FAmag and bare CuFe nanoparticles. The FAmag@CS@CuFe catalyst showed efficiency and stability in the conversion of 4-NPh of up to 95% in 3 min over four consecutive cycles. Such remarkable catalytic results demonstrate the potential of this catalyst as a substitute for expensive noble metals.
{"title":"Highly Efficient and Magnetically Recyclable Non-Noble Metal Fly Ash-Based Catalysts for 4-Nitrophenol Reduction","authors":"I. Kuźniarska-Biernacka, Inês Ferreira, Marta Monteiro, A. C. Santos, Bruno Valentim, Alexandra Guedes, João H. Belo, João P. Araújo, Cristina Freire, A. F. Peixoto","doi":"10.3390/catal14010003","DOIUrl":"https://doi.org/10.3390/catal14010003","url":null,"abstract":"4-nitrophenol (4-NPh) is a harmful compound produced in large amounts in the chemical industry, and its reduction to aminophenol (4-APh) using noble metals as catalysts is one of the most studied processes. The development of noble metal-free catalysts represents an economic advantage in large-scale applications and contributes to the sustainability of raw materials. Coal fly ash (FA), a major waste stream from coal combustion, contains an easily recoverable magnetic fraction (FAmag sample) composed of Fe-rich particles that could substitute noble metal catalysts in 4-NPh reduction, with the concomitant advantage of being easily recovered via magnetic separation. For this purpose, a new composite material containing copper ferrite nanoparticles (FAmag@CS@CuFe) was prepared via a facile, environmentally friendly and cost-effective method based on three components: FAmag as the core, a biobased polymer chitosan (CS) as the linker and copper ferrite CuFe2O4 nanoparticles (CuFe) as the active sites. The structure, morphology, composition and magnetic properties of the FAmag@CS@CuFe material were studied to assess the efficiency of the preparation. It was found that the biopolymer prevented the aggregation of CuFe nanoparticles and enabled a synergistically outstanding activity towards the reduction of 4-NPh in comparison to the pristine FAmag and bare CuFe nanoparticles. The FAmag@CS@CuFe catalyst showed efficiency and stability in the conversion of 4-NPh of up to 95% in 3 min over four consecutive cycles. Such remarkable catalytic results demonstrate the potential of this catalyst as a substitute for expensive noble metals.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":" 76","pages":""},"PeriodicalIF":3.9,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138962225","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}
Marcelo Tavares Lima, Nouridine Ousseini Salifou, G. V. Brigagão, Ivaldo Itabaiana Junior, R. Wojcieszak
Exploring the potential of utilizing CO2 for commercial purposes is a promising opportunity, especially in light of the growing research efforts towards CO2 capture, storage, and utilization as well as green H2 production. This review article delves into catalyst features and other technological aspects of a plausible process for the indirect conversion of CO2 into glycolic acid, which involves the following steps: CO2 capture, water electrolysis, CO2 hydrogenation to methanol, catalytic oxidation to formaldehyde, and formaldehyde carbonylation to glycolic acid. We adopt an industrial perspective to address this challenge effectively, thoroughly evaluating different processing alternatives with emphasis on the catalytic systems to optimize glycolic acid production performance.
{"title":"Conversion of CO2 into Glycolic Acid: A Review of Main Steps and Future Challenges","authors":"Marcelo Tavares Lima, Nouridine Ousseini Salifou, G. V. Brigagão, Ivaldo Itabaiana Junior, R. Wojcieszak","doi":"10.3390/catal14010004","DOIUrl":"https://doi.org/10.3390/catal14010004","url":null,"abstract":"Exploring the potential of utilizing CO2 for commercial purposes is a promising opportunity, especially in light of the growing research efforts towards CO2 capture, storage, and utilization as well as green H2 production. This review article delves into catalyst features and other technological aspects of a plausible process for the indirect conversion of CO2 into glycolic acid, which involves the following steps: CO2 capture, water electrolysis, CO2 hydrogenation to methanol, catalytic oxidation to formaldehyde, and formaldehyde carbonylation to glycolic acid. We adopt an industrial perspective to address this challenge effectively, thoroughly evaluating different processing alternatives with emphasis on the catalytic systems to optimize glycolic acid production performance.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":" 11","pages":""},"PeriodicalIF":3.9,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138962732","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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