Shan Jiang, Che-Wei Chang, William A Swann, Christina W. Li, Jeffrey T. Miller
Ethane dehydroaromatization (EDA) is a potentially attractive process for converting ethane to valuable aromatics such as benzene, toluene, and xylene (BTX). In this study, a Pt3Mn/SiO2 + ZSM-5 bifunctional catalyst was used to investigate the effect of dehydrogenation and the Brønsted acid catalyst ratio, hydrogen partial pressure, and reaction temperature on the product distributions for EDA. Pt3Mn/SiO2 + ZSM-5 with a 1/1 weight ratio showed the highest ethane conversion rate and BTX formation rate. Ethylene is initially formed by dehydrogenation by the Pt3Mn catalyst, which undergoes secondary reactions on ZSM-5, forming C3+ reaction intermediates. The latter form final products of CH4 and BTX. At conversions from 15 to 30%, the BTX selectivities are 82–90%. For all bifunctional catalysts, the ethane conversion significantly exceeds the ethane–ethylene equilibrium conversion due to reaction to secondary products. Low H2 partial pressures did not significantly alter the product selectivity or conversion. However, higher H2 partial pressures resulted in increased methane and decreased BTX selectivity. The excess hydrogen saturated the olefin intermediates to form alkanes, which produced methane by monomolecular cracking on ZSM-5. With an increasing reaction temperature from 550 °C to 650 °C, the benzene selectivity increased, while the highest BTX selectivity was obtained at 600 to 650 °C.
{"title":"Pt3Mn/SiO2 + ZSM-5 Bifunctional Catalyst for Ethane Dehydroaromatization","authors":"Shan Jiang, Che-Wei Chang, William A Swann, Christina W. Li, Jeffrey T. Miller","doi":"10.3390/catal14060365","DOIUrl":"https://doi.org/10.3390/catal14060365","url":null,"abstract":"Ethane dehydroaromatization (EDA) is a potentially attractive process for converting ethane to valuable aromatics such as benzene, toluene, and xylene (BTX). In this study, a Pt3Mn/SiO2 + ZSM-5 bifunctional catalyst was used to investigate the effect of dehydrogenation and the Brønsted acid catalyst ratio, hydrogen partial pressure, and reaction temperature on the product distributions for EDA. Pt3Mn/SiO2 + ZSM-5 with a 1/1 weight ratio showed the highest ethane conversion rate and BTX formation rate. Ethylene is initially formed by dehydrogenation by the Pt3Mn catalyst, which undergoes secondary reactions on ZSM-5, forming C3+ reaction intermediates. The latter form final products of CH4 and BTX. At conversions from 15 to 30%, the BTX selectivities are 82–90%. For all bifunctional catalysts, the ethane conversion significantly exceeds the ethane–ethylene equilibrium conversion due to reaction to secondary products. Low H2 partial pressures did not significantly alter the product selectivity or conversion. However, higher H2 partial pressures resulted in increased methane and decreased BTX selectivity. The excess hydrogen saturated the olefin intermediates to form alkanes, which produced methane by monomolecular cracking on ZSM-5. With an increasing reaction temperature from 550 °C to 650 °C, the benzene selectivity increased, while the highest BTX selectivity was obtained at 600 to 650 °C.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141268386","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}
Cheng Song, Lanqing Xiao, Yan Chen, Fan Yang, Huiying Meng, Wanying Zhang, Yifan Zhang, Yang Wu
TiO2-based catalysts with various surface heterostructures (0D, 1D, 2D, and 3D) have been widely researched owing to their cost-effectiveness, high stability, and environmentally friendly nature, and can be used for many applications in various fields, including hydrogen production and pollutant degradation. However, there are also many existing problems limiting their practical application, such as their large band gap and rapid electron–hole recombination rate. Owing to the abundance of recent achievements in materials science, we will summarize the recent structural engineering strategies which provide favorable photocatalytic activity enhancements, such as enhanced visible light absorption, stability, an increased charge–carrier separation rate and improved specific surface area. Among the various structural engineering methods in this review, we will introduce TiO2-based materials with different dimensional structures. Meanwhile, we also discuss recent achievements in synthesis methods and application of TiO2-based catalysts in various fields. We aim to display a comprehensive overview which can be a guide for the development of a new generation of TiO2-based catalysts according to their structural design for enhanced solar energy conversion.
{"title":"TiO2-Based Catalysts with Various Structures for Photocatalytic Application: A Review","authors":"Cheng Song, Lanqing Xiao, Yan Chen, Fan Yang, Huiying Meng, Wanying Zhang, Yifan Zhang, Yang Wu","doi":"10.3390/catal14060366","DOIUrl":"https://doi.org/10.3390/catal14060366","url":null,"abstract":"TiO2-based catalysts with various surface heterostructures (0D, 1D, 2D, and 3D) have been widely researched owing to their cost-effectiveness, high stability, and environmentally friendly nature, and can be used for many applications in various fields, including hydrogen production and pollutant degradation. However, there are also many existing problems limiting their practical application, such as their large band gap and rapid electron–hole recombination rate. Owing to the abundance of recent achievements in materials science, we will summarize the recent structural engineering strategies which provide favorable photocatalytic activity enhancements, such as enhanced visible light absorption, stability, an increased charge–carrier separation rate and improved specific surface area. Among the various structural engineering methods in this review, we will introduce TiO2-based materials with different dimensional structures. Meanwhile, we also discuss recent achievements in synthesis methods and application of TiO2-based catalysts in various fields. We aim to display a comprehensive overview which can be a guide for the development of a new generation of TiO2-based catalysts according to their structural design for enhanced solar energy conversion.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141266862","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}
Qiaoting Cheng, Hu Ding, Lang Chen, Jiatong Dong, Hao Yu, Shen Yan, Hua Wang
The two-electron oxygen reduction reaction (2e− ORR) has emerged as an attractive alternative for H2O2 production. Developing efficient earth-abundant transition metal electrocatalysts and reaction mechanism exploration for H2O2 production are important but remain challenging. Herein, a nitrogen-doped carbon-coated NiSe2 (NiSe2@NC) electrocatalyst was prepared by successive annealing treatment. Benefiting from the synergistic effect between the NiSe2 nanoparticles and NC, the 2e− ORR activity, selectivity, and stability of NiSe2@NC in 0.1 M HClO4 was greatly enhanced, with the yield of H2O2 being 4.4 times that of the bare NiSe2 nanoparticles. The in situ Raman spectra and density functional theory (DFT) calculation revealed that the presence of NC was beneficial for regulating the electronic state of NiSe2 and optimizing the adsorption free energy of *OOH, which could enhance the adsorption of O2, stabilize the O-O bond, and boost the production of H2O2. This work provides an effective strategy to improve the performance of the transition metal chalcogenide for 2e− ORR to H2O2.
{"title":"Modification of NiSe2 Nanoparticles by ZIF-8-Derived NC for Boosting H2O2 Production from Electrochemical Oxygen Reduction in Acidic Media","authors":"Qiaoting Cheng, Hu Ding, Lang Chen, Jiatong Dong, Hao Yu, Shen Yan, Hua Wang","doi":"10.3390/catal14060364","DOIUrl":"https://doi.org/10.3390/catal14060364","url":null,"abstract":"The two-electron oxygen reduction reaction (2e− ORR) has emerged as an attractive alternative for H2O2 production. Developing efficient earth-abundant transition metal electrocatalysts and reaction mechanism exploration for H2O2 production are important but remain challenging. Herein, a nitrogen-doped carbon-coated NiSe2 (NiSe2@NC) electrocatalyst was prepared by successive annealing treatment. Benefiting from the synergistic effect between the NiSe2 nanoparticles and NC, the 2e− ORR activity, selectivity, and stability of NiSe2@NC in 0.1 M HClO4 was greatly enhanced, with the yield of H2O2 being 4.4 times that of the bare NiSe2 nanoparticles. The in situ Raman spectra and density functional theory (DFT) calculation revealed that the presence of NC was beneficial for regulating the electronic state of NiSe2 and optimizing the adsorption free energy of *OOH, which could enhance the adsorption of O2, stabilize the O-O bond, and boost the production of H2O2. This work provides an effective strategy to improve the performance of the transition metal chalcogenide for 2e− ORR to H2O2.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141269824","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}
Direct upgrading of methane into value-added products is one of the most significant technologies for the effective transformation of hydrocarbon feedstocks in the chemical industry. Both oxidative and non-oxidative methane conversion are broadly useful approaches, though the two reaction pathways are quite distinguished. Oxidative coupling of methane (OCM) has been widely studied, but suffers from the low selectivity to C2 hydrocarbons because of the overoxidation leading to undesired byproducts. Therefore, non-oxidative coupling of methane is a worthy alternative approach to be developed for the efficient, direct utilization of methane. Recently, heterogeneous catalysts comprising singly dispersed metal sites, such as single-atom catalysts (SAC) and surface organometallic catalysts (SOMCat), have been proven to be effectively active for direct coupling of methane to product hydrogen and C2 products. In this context, this review summarizes recent discoveries of these novel catalysts and provides a perspective on promising catalytic processes for methane transformation via non-oxidative coupling.
{"title":"Non-Oxidative Coupling of Methane Catalyzed by Heterogeneous Catalysts Containing Singly Dispersed Metal Sites","authors":"Yuting Li, Jie Zhang","doi":"10.3390/catal14060363","DOIUrl":"https://doi.org/10.3390/catal14060363","url":null,"abstract":"Direct upgrading of methane into value-added products is one of the most significant technologies for the effective transformation of hydrocarbon feedstocks in the chemical industry. Both oxidative and non-oxidative methane conversion are broadly useful approaches, though the two reaction pathways are quite distinguished. Oxidative coupling of methane (OCM) has been widely studied, but suffers from the low selectivity to C2 hydrocarbons because of the overoxidation leading to undesired byproducts. Therefore, non-oxidative coupling of methane is a worthy alternative approach to be developed for the efficient, direct utilization of methane. Recently, heterogeneous catalysts comprising singly dispersed metal sites, such as single-atom catalysts (SAC) and surface organometallic catalysts (SOMCat), have been proven to be effectively active for direct coupling of methane to product hydrogen and C2 products. In this context, this review summarizes recent discoveries of these novel catalysts and provides a perspective on promising catalytic processes for methane transformation via non-oxidative coupling.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141273950","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}
D. Brüggemann, P. Isbrücker, Dzenna Zukova, Franz Robert Otto Heinrich Schröter, Yen Hoang Le, Reinhard Schomäcker
The preparation of CO2-containing polymers with improved degradation properties is still very challenging. An elegant method for preparing these polymers is to use CO2-containing monomers in ring-opening polymerizations (ROP) which are particularly gentle and energy-saving methods. However, cyclic carbonates are required for this which are not readily available. This paper therefore aims to present the optimization and comparison of two synthesis methods to obtain cyclic carbonates for ROP. Within this work, cyclic styrene carbonate was synthesized from readily available raw materials by using a Jacobsen catalyst for the reaction of styrene oxide and carbon dioxide or an organocatalyst for the transesterification of methyl carbonate with 1-phenyl-1,2-ethanediol. The latter performed with 100% selectivity to the desired styrene carbonate, which was succesfully tested in ROP, producing an amorphous thermoplastic polymer with a TG of 185 ∘C.
{"title":"Investigation and Comparison of Catalytic Methods to Produce Green CO2-Containing Monomers for Polycarbonates","authors":"D. Brüggemann, P. Isbrücker, Dzenna Zukova, Franz Robert Otto Heinrich Schröter, Yen Hoang Le, Reinhard Schomäcker","doi":"10.3390/catal14060362","DOIUrl":"https://doi.org/10.3390/catal14060362","url":null,"abstract":"The preparation of CO2-containing polymers with improved degradation properties is still very challenging. An elegant method for preparing these polymers is to use CO2-containing monomers in ring-opening polymerizations (ROP) which are particularly gentle and energy-saving methods. However, cyclic carbonates are required for this which are not readily available. This paper therefore aims to present the optimization and comparison of two synthesis methods to obtain cyclic carbonates for ROP. Within this work, cyclic styrene carbonate was synthesized from readily available raw materials by using a Jacobsen catalyst for the reaction of styrene oxide and carbon dioxide or an organocatalyst for the transesterification of methyl carbonate with 1-phenyl-1,2-ethanediol. The latter performed with 100% selectivity to the desired styrene carbonate, which was succesfully tested in ROP, producing an amorphous thermoplastic polymer with a TG of 185 ∘C.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141280376","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}
M. Shanmugam, Nithish Agamendran, Karthikeyan Sekar
Using a p-n heterojunction is one of the efficient methods to increase charge transfer in photocatalysis applications. So, herein, p-type UiO-66 (NH2) and n-type CuFe2O4 (CFO) are used to form an effective p-n heterojunction. Due to their poor charge separation in their pristine form, both UiO-66 (NH2) and CFO materials cannot produce hydrogen; however, the composite p-n heterojunction formed between these materials makes fast charge separation and so hydrogen is efficiently produced. The optimized catalyst UCFO 25% produces a maximum of 62.5 µmol/g/h hydrogen in an aqueous methanol solution. The formation of a p-n heterojunction is confirmed by Mott–Schottky analysis and optical properties, crystallinity and the local atomic environment of the material was analyzed by various analytical tools like UV-Vis spectroscopy, XRD, and XANES.
{"title":"Efficient Charge Transfer of p-n Heterojunction UiO-66-NH2/CuFe2O4 Composite for Photocatalytic Hydrogen Production","authors":"M. Shanmugam, Nithish Agamendran, Karthikeyan Sekar","doi":"10.3390/catal14060341","DOIUrl":"https://doi.org/10.3390/catal14060341","url":null,"abstract":"Using a p-n heterojunction is one of the efficient methods to increase charge transfer in photocatalysis applications. So, herein, p-type UiO-66 (NH2) and n-type CuFe2O4 (CFO) are used to form an effective p-n heterojunction. Due to their poor charge separation in their pristine form, both UiO-66 (NH2) and CFO materials cannot produce hydrogen; however, the composite p-n heterojunction formed between these materials makes fast charge separation and so hydrogen is efficiently produced. The optimized catalyst UCFO 25% produces a maximum of 62.5 µmol/g/h hydrogen in an aqueous methanol solution. The formation of a p-n heterojunction is confirmed by Mott–Schottky analysis and optical properties, crystallinity and the local atomic environment of the material was analyzed by various analytical tools like UV-Vis spectroscopy, XRD, and XANES.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141099425","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}
Water pollution is one of the main challenges currently facing scientists around the world because of the rapid growth in industrial activities. On this basis, 2D nanolayered and nanohybrid structures, which are based on a ternary system of nickel–titanium–zinc, are considered favorable sources for designing effective nanocomposites for the photocatalytic degradation of industrial pollutants in a short period of time. These nanocomposites were designed by modifying two-dimensional nanolayers to produce a three-dimensional porous structure of multi-doped Ni/Ti-ZnO nanocomposites. Additionally, another additive was produced by constructing nanohybrids of nickel–titanium–zinc combined with a series of hydrocarbons (n-capric acid, myristic acid, stearic acid, suberic acid, and sebacic acid). Energy-dispersive X-ray spectrometry, X-ray diffraction, scanning electron microscopy, infrared spectroscopy, and thermal analyses confirmed the growth of the nanolayered and nanohybrid materials in addition to the production of nanocomposites. The positive role of the dopants (nickel and titanium) in producing an effective photocatalyst was observed through a significant narrowing of the band gap of zinc oxide to 3.05–3.10 eV. Additionally, the high photocatalytic activity of this nanocomposite enabled the complete removal of colored dye from water after 25 min of UV radiation. In conclusion, this study proposes an unconventional approach for designing new optical nanocomposites for purifying water. Additionally, it suggests a novel supporting method for designing new kinds of nanohybrids based on multi-metals and organic acids.
由于工业活动的快速增长，水污染是全球科学家目前面临的主要挑战之一。在此基础上，基于镍-钛-锌三元体系的二维纳米层和纳米杂化结构被认为是设计有效纳米复合材料的有利来源，可在短时间内光催化降解工业污染物。这些纳米复合材料是通过修改二维纳米层来设计的，以产生多掺杂镍/钛锌纳米复合材料的三维多孔结构。此外，通过构建镍-钛-锌与一系列碳氢化合物（正辛酸、肉豆蔻酸、硬脂酸、辛二酸和癸二酸）结合的纳米杂化物，还制备了另一种添加剂。能量色散 X 射线光谱、X 射线衍射、扫描电子显微镜、红外光谱和热分析证实了纳米层状和纳米杂化材料的生长，以及纳米复合材料的生产。通过将氧化锌的带隙显著缩小至 3.05-3.10 eV，可以观察到掺杂剂（镍和钛）在产生有效光催化剂方面的积极作用。此外，这种纳米复合材料具有很高的光催化活性，在紫外线照射 25 分钟后就能完全去除水中的有色染料。总之，本研究提出了一种非常规的方法来设计用于净化水的新型光学纳米复合材料。此外，它还为设计基于多金属和有机酸的新型纳米混合物提出了一种新颖的辅助方法。
{"title":"Engineering the Integration of Titanium and Nickel into Zinc Oxide Nanocomposites through Nanolayered Structures and Nanohybrids to Design Effective Photocatalysts for Purifying Water from Industrial Pollutants","authors":"O. Saber, A. Osama, N. Shaalan, Mostafa Osama","doi":"10.3390/catal14060340","DOIUrl":"https://doi.org/10.3390/catal14060340","url":null,"abstract":"Water pollution is one of the main challenges currently facing scientists around the world because of the rapid growth in industrial activities. On this basis, 2D nanolayered and nanohybrid structures, which are based on a ternary system of nickel–titanium–zinc, are considered favorable sources for designing effective nanocomposites for the photocatalytic degradation of industrial pollutants in a short period of time. These nanocomposites were designed by modifying two-dimensional nanolayers to produce a three-dimensional porous structure of multi-doped Ni/Ti-ZnO nanocomposites. Additionally, another additive was produced by constructing nanohybrids of nickel–titanium–zinc combined with a series of hydrocarbons (n-capric acid, myristic acid, stearic acid, suberic acid, and sebacic acid). Energy-dispersive X-ray spectrometry, X-ray diffraction, scanning electron microscopy, infrared spectroscopy, and thermal analyses confirmed the growth of the nanolayered and nanohybrid materials in addition to the production of nanocomposites. The positive role of the dopants (nickel and titanium) in producing an effective photocatalyst was observed through a significant narrowing of the band gap of zinc oxide to 3.05–3.10 eV. Additionally, the high photocatalytic activity of this nanocomposite enabled the complete removal of colored dye from water after 25 min of UV radiation. In conclusion, this study proposes an unconventional approach for designing new optical nanocomposites for purifying water. Additionally, it suggests a novel supporting method for designing new kinds of nanohybrids based on multi-metals and organic acids.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141101429","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}
Song Zou, Zheng Wang, Yizhou Wang, Yanping Ma, Yang Sun, Wen-Hua Sun
In this study, 2-t-butyl-4-arylimino-2,3-dihydroacridylnickel dibromides were synthesized by nickel-template one-pot condensation, and well characterized along with the single-crystal X-ray diffraction to one representative complex, revealing a distorted tetrahedral geometry around nickel. When activated with modified methylaluminoxane (MMAO), all nickel complexes exhibited high activities (up to 1.91 × 106 g mol−1 (Ni) h−1) toward major trimerization of ethylene. When activated with ethylaluminum dichloride (EtAlCl2), however, the title complexes performed good activities (up to 1.05 × 106 g mol−1 (Ni) h−1) for selective dimerization of ethylene. In comparison to analogous nickel complexes, higher activities were achieved with the substituent of t-butyl group, especially in the rare case of nickel complexes performing trimerization of ethylene.
本研究通过镍模板一锅缩合法合成了 2-t-丁基-4-芳基亚氨基-2,3-二氢吖啶基镍二溴化物，并对其中一个代表性络合物进行了单晶 X 射线衍射表征，发现镍周围存在扭曲的四面体几何形状。当用改性甲基铝氧烷（MMAO）激活时，所有镍络合物都表现出很高的活性（高达 1.91 × 106 g mol-1 (Ni) h-1），可实现乙烯的主要三聚化。然而，当用二氯化铝（EtAlCl2）激活时，标题络合物在乙烯的选择性二聚化方面表现出良好的活性（高达 1.05 × 106 g mol-1 (Ni) h-1）。与类似的镍络合物相比，以叔丁基为取代基的镍络合物具有更高的活性，尤其是在镍络合物对乙烯进行三聚的罕见情况下。
{"title":"On-Purpose Oligomerization by 2-t-Butyl-4-arylimino-2,3-dihydroacridylnickel(II) Bromides","authors":"Song Zou, Zheng Wang, Yizhou Wang, Yanping Ma, Yang Sun, Wen-Hua Sun","doi":"10.3390/catal14060342","DOIUrl":"https://doi.org/10.3390/catal14060342","url":null,"abstract":"In this study, 2-t-butyl-4-arylimino-2,3-dihydroacridylnickel dibromides were synthesized by nickel-template one-pot condensation, and well characterized along with the single-crystal X-ray diffraction to one representative complex, revealing a distorted tetrahedral geometry around nickel. When activated with modified methylaluminoxane (MMAO), all nickel complexes exhibited high activities (up to 1.91 × 106 g mol−1 (Ni) h−1) toward major trimerization of ethylene. When activated with ethylaluminum dichloride (EtAlCl2), however, the title complexes performed good activities (up to 1.05 × 106 g mol−1 (Ni) h−1) for selective dimerization of ethylene. In comparison to analogous nickel complexes, higher activities were achieved with the substituent of t-butyl group, especially in the rare case of nickel complexes performing trimerization of ethylene.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141102053","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}
There are plenty of challenges related to the current energy situation [...]
当前的能源形势面临诸多挑战 [...]
{"title":"Editorial: Biomass Derived Heterogeneous and Homogeneous Catalysts, 2nd Edition","authors":"José María Encinar Martín, S. Nogales-Delgado","doi":"10.3390/catal14060339","DOIUrl":"https://doi.org/10.3390/catal14060339","url":null,"abstract":"There are plenty of challenges related to the current energy situation [...]","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141105224","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}
Excessive emissions of carbon dioxide have led to the greenhouse effect and global warming. Reducing carbon dioxide into high-value-added chemicals through solar energy is a promising approach. Herein, a g-C3N4/TiO2 heterojunction photocatalyst with efficient electron transfer is designed for photocatalytic CO2 reduction. The CH4 (18.32 µmol·h−1·g−1) and CO (25.35 µmol·h−1·g−1) evolution rates of g-C3N4/TiO2 are higher than those of g-C3N4 and TiO2. The enhanced photocatalytic CO2 reduction performance is attributed to the efficient charge carrier transfer in the g-C3N4/TiO2 heterojunction. The electron transfer route was verified by in situ irradiated X-ray photoelectron spectroscopy (XPS). The photocatalytic CO2 reduction mechanism on g-C3N4/TiO2 was investigated by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). This work provides a strategy for designing a polymer/metallic oxide heterojunction with efficient electron transfer for enhanced photocatalytic CO2 reduction.
二氧化碳的过度排放导致了温室效应和全球变暖。通过太阳能将二氧化碳还原成高附加值化学品是一种前景广阔的方法。本文设计了一种具有高效电子传递功能的 g-C3N4/TiO2 异质结光催化剂，用于光催化还原二氧化碳。g-C3N4/TiO2 的 CH4（18.32 µmol-h-1-g-1）和 CO（25.35 µmol-h-1-g-1）演化率高于 g-C3N4 和 TiO2。光催化还原 CO2 性能的提高归功于 g-C3N4/TiO2 异质结中高效的电荷载流子转移。原位辐照 X 射线光电子能谱（XPS）验证了电子转移途径。通过原位漫反射红外傅里叶变换光谱（DRIFTS）研究了 g-C3N4/TiO2 光催化还原 CO2 的机理。这项研究为设计具有高效电子传递功能的聚合物/金属氧化物异质结以增强光催化还原 CO2 提供了一种策略。
{"title":"Efficient Electron Transfer in g-C3N4/TiO2 Heterojunction for Enhanced Photocatalytic CO2 Reduction","authors":"Peng Jiang, Yang Yu, Kun Wang, Wenrui Liu","doi":"10.3390/catal14060335","DOIUrl":"https://doi.org/10.3390/catal14060335","url":null,"abstract":"Excessive emissions of carbon dioxide have led to the greenhouse effect and global warming. Reducing carbon dioxide into high-value-added chemicals through solar energy is a promising approach. Herein, a g-C3N4/TiO2 heterojunction photocatalyst with efficient electron transfer is designed for photocatalytic CO2 reduction. The CH4 (18.32 µmol·h−1·g−1) and CO (25.35 µmol·h−1·g−1) evolution rates of g-C3N4/TiO2 are higher than those of g-C3N4 and TiO2. The enhanced photocatalytic CO2 reduction performance is attributed to the efficient charge carrier transfer in the g-C3N4/TiO2 heterojunction. The electron transfer route was verified by in situ irradiated X-ray photoelectron spectroscopy (XPS). The photocatalytic CO2 reduction mechanism on g-C3N4/TiO2 was investigated by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). This work provides a strategy for designing a polymer/metallic oxide heterojunction with efficient electron transfer for enhanced photocatalytic CO2 reduction.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141109438","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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