摘要
Selective hydrogenation of acetylene in excess ethylene is an important reaction in both fundamental study and practical application.Pd-based catalysts with high intrinsic activity are commonly employed,but usually suffer from low selectivity.Pd single-atom catalysts(SACs)usually exhibit outstanding ethylene selectivity due to the weakπ-bonding ethylene adsorption.However,the preparation of high-loading and stable Pd SACs is still confronted with a great challenge.In this work,we report a simple strategy to fabricate Pd SACs by means of reducing conventional supported Pd catalysts at suitable temperatures to selectively encapsulate the co-existed Pd nanoparticles(NPs)/clusters.This is based on our new finding that single atoms only manifest strong metal-support interaction(SMSI)at higher reduction temperature than that of NPs/clusters.The derived Pd SACs(Pd1/CeO2 and Pd1/a-Fe2O3)were applied to acetylene selective hydrogenation,exhibiting much improved ethylene selectivity and high stability.This work offers a promising way to develop stable Pd SACs easily.
基金
financially supported by the National Natural Science Foundation of China(Nos.21972135,21961142006,and 51701201)
CAS Project for Young Scientists in Basic Research(No.YSBR-022)
the National Key Research and Development Program of China(No.2021YFA1500503)。