Single-atom site(SA)catalysts on N-doped carbon(CN)materials exhibit prominent performance for their active sites being M-Nx.Due to the commonly random doping behaviors of N species in these CN,it is a tough issue to ...Single-atom site(SA)catalysts on N-doped carbon(CN)materials exhibit prominent performance for their active sites being M-Nx.Due to the commonly random doping behaviors of N species in these CN,it is a tough issue to finely regulate their doping types and clarify their effect on the catalytic property of such catalysts.Herein,we report that the N-doping type in CN can be dominated as pyrrolic-N and pyridinic-N respectively through compounding with different metal oxides.It is found that the proportion of distinct doped N species in CN depends on the acidity and basicity of compounded metal oxide host.Owing to the coordination by pyrrolic-N,the SA Cu catalyst displays an enhanced activity(two-fold)for transfer hydrogenation of quinoline to access the valuable molecule tetrahydroquinoline with a good selectivity(99%)under mild conditions.The higher electron density of SA Cu species induced by the predominate pyrrolic-N coordination benefits the hydrogen transfer process and reduces the energy barrier of the hydrogenation pathway,which accounts for the improved catalytic effeciency.展开更多
基金supported by the National Key R&D Program of China(Nos.2018YFA0702003 and 2016YFA0202801)the National Natural Science Foundation of China(Nos.21890383,21671117,21871159,and 21901135)+2 种基金the National Postdoctoral Program for Innovative Talents,the Shuimu Tsinghua Scholar,Science and Technology Key Project of Guangdong Province of China(No.2020B010188002)Beijing Municipal Science&Technology Commission(No.Z191100007219003)We thank the BL14W1 station in Shanghai Synchrotron Radiation Facility(SSRF)and 1W1B station for XAFS measurement in Beijing Synchrotron Radiation Facility(BSRF).
文摘Single-atom site(SA)catalysts on N-doped carbon(CN)materials exhibit prominent performance for their active sites being M-Nx.Due to the commonly random doping behaviors of N species in these CN,it is a tough issue to finely regulate their doping types and clarify their effect on the catalytic property of such catalysts.Herein,we report that the N-doping type in CN can be dominated as pyrrolic-N and pyridinic-N respectively through compounding with different metal oxides.It is found that the proportion of distinct doped N species in CN depends on the acidity and basicity of compounded metal oxide host.Owing to the coordination by pyrrolic-N,the SA Cu catalyst displays an enhanced activity(two-fold)for transfer hydrogenation of quinoline to access the valuable molecule tetrahydroquinoline with a good selectivity(99%)under mild conditions.The higher electron density of SA Cu species induced by the predominate pyrrolic-N coordination benefits the hydrogen transfer process and reduces the energy barrier of the hydrogenation pathway,which accounts for the improved catalytic effeciency.
