Ammonia borane(NH_(3)BH_(3),AB)has been regarded as a promising chemical hydrogen storage material owing to its high hydrogen density and superior stability.Thus,the development of low-cost and high-efficient heteroge...Ammonia borane(NH_(3)BH_(3),AB)has been regarded as a promising chemical hydrogen storage material owing to its high hydrogen density and superior stability.Thus,the development of low-cost and high-efficient heterogeneous catalysts for the dehydrogenation of AB has attracted considerable scholarly attention.In this study,heterostructured Co_(3)O_(4)-SnO_(2)catalysts containing oxygen vacancy(V_(o))with different Co/Sn atomic ratios(designated as V_(o)-Co-Sn_(5:x))were synthesized via a simple coprecipitation-calcination method under mild reaction conditions.The catalyst containing an optimized Co/Sn atomic ratio of 5:2(V_(o)-Co-Sn_(5:2))exhibited robust catalytic performance with a turnover frequency value of 17.6mol_(H2)·mol^(-1)_(metal)·min^(-1).Moreover,82.6%of the original activity of the catalyst was retained after 14 catalytic cycles,indicating the high stability of the catalyst.Diversified characterization combined with the density functional theory(DFT)calculation confirmed the transfer of electrons from Co_(3)O_(4)to Sn O_(2)and the distribution of the separated charges on SnO_(2)-Co_(3)O_(4)interface.The transfer of electrons and the distribution of charges facilitated the adsorption and activation of water on the catalyst,thus accelerating the dissociation of H_(2)O molecule(the ratedetermining step of AB hydrolysis).It was found that the V_(o)adjusted the electron structure of the catalysts rather than acted as active sites.These findings will provide researchers with useful information for designing cheap and highly efficient catalysts for catalytic AB hydrolysis.展开更多
基金financially supported by the Professorial and Doctoral Scientific Research Foundation of Huizhou University(Nos.2018JB036,2020JB046 and 2022JB009)the Major and Special Project in the Field of Intelligent Manufacturing of the Universities in Guangdong Province(No.2020ZDZX2067)+3 种基金the Natural Science Foundation of Huizhou University(No.HZU202004)Open Project Program of Guangdong Provincial Key Laboratory of Electronic Functional Materials and Devices,Huizhou University(Nos.EFMDN2021001Z and EFMDN2021004M)Youth Innovative Talents Project in Collegesand Universities in Guangdong Province(No.2019KQNCX151)Basic and Applied Basic Research Fund of Guangdong Province(No.2020A1515110038)。
文摘Ammonia borane(NH_(3)BH_(3),AB)has been regarded as a promising chemical hydrogen storage material owing to its high hydrogen density and superior stability.Thus,the development of low-cost and high-efficient heterogeneous catalysts for the dehydrogenation of AB has attracted considerable scholarly attention.In this study,heterostructured Co_(3)O_(4)-SnO_(2)catalysts containing oxygen vacancy(V_(o))with different Co/Sn atomic ratios(designated as V_(o)-Co-Sn_(5:x))were synthesized via a simple coprecipitation-calcination method under mild reaction conditions.The catalyst containing an optimized Co/Sn atomic ratio of 5:2(V_(o)-Co-Sn_(5:2))exhibited robust catalytic performance with a turnover frequency value of 17.6mol_(H2)·mol^(-1)_(metal)·min^(-1).Moreover,82.6%of the original activity of the catalyst was retained after 14 catalytic cycles,indicating the high stability of the catalyst.Diversified characterization combined with the density functional theory(DFT)calculation confirmed the transfer of electrons from Co_(3)O_(4)to Sn O_(2)and the distribution of the separated charges on SnO_(2)-Co_(3)O_(4)interface.The transfer of electrons and the distribution of charges facilitated the adsorption and activation of water on the catalyst,thus accelerating the dissociation of H_(2)O molecule(the ratedetermining step of AB hydrolysis).It was found that the V_(o)adjusted the electron structure of the catalysts rather than acted as active sites.These findings will provide researchers with useful information for designing cheap and highly efficient catalysts for catalytic AB hydrolysis.
