Cobalt carbide(Co2C)was considered as potential catalysts available for large-scale industrialization of transforming syngas(H2 and CO)to clean fuels.Herein,we successfully synthesized Co-based catalysts with MnO supp...Cobalt carbide(Co2C)was considered as potential catalysts available for large-scale industrialization of transforming syngas(H2 and CO)to clean fuels.Herein,we successfully synthesized Co-based catalysts with MnO supported,to comprehend the effects of Co2C for Fischer–Tropsch synthesis(FTS)under ambient conditions.The huge variety of product selectivity which was contained by different active sites(Co and Co2C)has been found.Furthermore,density functional theory(DFT)shows that Co2C is efficacious of CO adsorption,whereas is weaker for H adsorption than Co.Combining the advantages of Co and Co2C,the catalyst herein can not only obtain more C5+products but also suppress methane selectivity.It can be a commendable guide for the design of industrial application products in FTS.展开更多
Pd nano cubes(NCs)en closed by six{100}facets are fasci nating model materials for both fun dame ntal studies and practical applicati ons.However,the only available method to prepare well-defined sub-10 nm Pd NCs was ...Pd nano cubes(NCs)en closed by six{100}facets are fasci nating model materials for both fun dame ntal studies and practical applicati ons.However,the only available method to prepare well-defined sub-10 nm Pd NCs was developed by Xia et al.more than 10 years ago,un avoidably using polyvinyl pyrrol id one(PVP)polymer to preve nt particle aggregati on.The strongly adsorbed PVP extremely deteriorates the catalysts*efficiency because of the high coverage of accessible surface-active sites.Numerous efforts have been devoted to replacing PVP with weaker capping agents but with limited progress predominately due to the difficulties in tuning the growth kinetics of Pd NCs.For the first time,we report that macrocycle cucurbit[6]uril(CB[6])can replace PVP in the synthesis of Pd NCs by dedicatedly controlling the growth parameters.CB[6]capped Pd NCs showed 1.1-1.5 times in creased specific surface area compared to the surfactant-free commercial Pd catalysts.Moreover,X-ray photoelectron spectroscopy dem on strated the modified electronic structure of Pd NCs through the carb onyl group of CB[6].Consequently,compared to the commercial catalysts,the obtained Pd NCs exhibited 7 times higher current density towards ethanol oxidation reaction.Remarkably,after 17 h of continuous work,it reduced deactivation by up to 1-4 orders of magnitude.展开更多
Anisotropic Pd nanoparticles with highly branched morphologies are urgently needed as building blocks for nanoscale devices, catalysts, and sensing materials owing to their novel structures and unique physicochemical ...Anisotropic Pd nanoparticles with highly branched morphologies are urgently needed as building blocks for nanoscale devices, catalysts, and sensing materials owing to their novel structures and unique physicochemical properties. However, realizing size control and branch manipulation for these materials is very challenging. In this study, we develop a facile ultrafine Cu seed-mediated approach in the aqueous phase to produce novel Pd-Cu trigonal hierarchical nanoframes （THNFs）. The main branch of most of the obtained nanocrystals is tripod-like, with advanced branches along the arms as frame units having self-similarity. In this method, the size of the Pd-Cu THNFs can be flexibly controlled by manipulating the nucleation involving the sub-3 nm Cu seeds. These Pd-Cu THNFs outperform Pd black with regard to their ethanol-oxidation performance, having a specific activity and mass activity 9.7 and 6.6 times higher, respectively. This research provides a versatile ultrafine seed-mediated approach for producing size-controlled anisotropic bimetallic nanoframes.展开更多
基金supported from the National Natural Science Foundation of China,Grant/Award Number:U1732267,21503218.
文摘Cobalt carbide(Co2C)was considered as potential catalysts available for large-scale industrialization of transforming syngas(H2 and CO)to clean fuels.Herein,we successfully synthesized Co-based catalysts with MnO supported,to comprehend the effects of Co2C for Fischer–Tropsch synthesis(FTS)under ambient conditions.The huge variety of product selectivity which was contained by different active sites(Co and Co2C)has been found.Furthermore,density functional theory(DFT)shows that Co2C is efficacious of CO adsorption,whereas is weaker for H adsorption than Co.Combining the advantages of Co and Co2C,the catalyst herein can not only obtain more C5+products but also suppress methane selectivity.It can be a commendable guide for the design of industrial application products in FTS.
基金The authors acknowledge the financial support from the National Key R&D Program of China(Nos.2017YFA0206800 and 2017YFA0700100)the National Natural Science Foundation of China(Nos.2157323&21571177,and 21520102001)+1 种基金Key Research Program of Frontier Sciences,CAS(No.QYZDJ-SSW-SLH045)"Strategic Priority Research ProgramM of the Chinese Academy of Sciences(No.XDB20000000).
文摘Pd nano cubes(NCs)en closed by six{100}facets are fasci nating model materials for both fun dame ntal studies and practical applicati ons.However,the only available method to prepare well-defined sub-10 nm Pd NCs was developed by Xia et al.more than 10 years ago,un avoidably using polyvinyl pyrrol id one(PVP)polymer to preve nt particle aggregati on.The strongly adsorbed PVP extremely deteriorates the catalysts*efficiency because of the high coverage of accessible surface-active sites.Numerous efforts have been devoted to replacing PVP with weaker capping agents but with limited progress predominately due to the difficulties in tuning the growth kinetics of Pd NCs.For the first time,we report that macrocycle cucurbit[6]uril(CB[6])can replace PVP in the synthesis of Pd NCs by dedicatedly controlling the growth parameters.CB[6]capped Pd NCs showed 1.1-1.5 times in creased specific surface area compared to the surfactant-free commercial Pd catalysts.Moreover,X-ray photoelectron spectroscopy dem on strated the modified electronic structure of Pd NCs through the carb onyl group of CB[6].Consequently,compared to the commercial catalysts,the obtained Pd NCs exhibited 7 times higher current density towards ethanol oxidation reaction.Remarkably,after 17 h of continuous work,it reduced deactivation by up to 1-4 orders of magnitude.
基金We acknowledge financial support from the National Basic Research Program of China （Nos. 2014CB845605 and 2013CB933200）, the National Natural Science Foundation of China （Nos. 21521061, 21573238, 21331006, 21571177, and 21520102001）, Strtegic Priority Research Program of the Chinese Academy of Sciences （No. XDB20000000）, the Natural Science Foundation of the Fujian Province （No. 2014J05022）, and the Chunmiao Project of the Haixi Institute of the Chinese Academy of Sciences （No. CMZX-2014-004）.
文摘Anisotropic Pd nanoparticles with highly branched morphologies are urgently needed as building blocks for nanoscale devices, catalysts, and sensing materials owing to their novel structures and unique physicochemical properties. However, realizing size control and branch manipulation for these materials is very challenging. In this study, we develop a facile ultrafine Cu seed-mediated approach in the aqueous phase to produce novel Pd-Cu trigonal hierarchical nanoframes （THNFs）. The main branch of most of the obtained nanocrystals is tripod-like, with advanced branches along the arms as frame units having self-similarity. In this method, the size of the Pd-Cu THNFs can be flexibly controlled by manipulating the nucleation involving the sub-3 nm Cu seeds. These Pd-Cu THNFs outperform Pd black with regard to their ethanol-oxidation performance, having a specific activity and mass activity 9.7 and 6.6 times higher, respectively. This research provides a versatile ultrafine seed-mediated approach for producing size-controlled anisotropic bimetallic nanoframes.
