Impact of Pd single-site coordination structure on catalytic performance for semihydrogenation of acetylene  

作　　者：Yu Zeng Minqi Xia Fujie Gao Changkai Zhou Xueyi Cheng Liwei Liu Liu Jiao Qiang Wu Xizhang Wang Lijun Yang Yining Fan Zheng Hu 

机构地区：[1]Key Laboratory of Mesoscopic Chemistry of MOE and Jiangsu Provincial Laboratory for Nanotechnology,School of Chemistry and Chemical Engineering,Nanjing University,Nanjing 210023,China

出　　处：《Nano Research》2024年第9期8243-8249,共7页纳米研究（英文版）

基　　金：supported by the National Key Research and Development Program of China(No.2021YFA1500900);the National Natural Science Foundation of China(No.52071174);the Natural Science Foundation of Jiangsu Province,Major Project(No.BK20212005).

摘　　要：Semihydrogenation of trace acetylene in an ethylene gas stream is a vital step for the industrial production of polyethylene,in which Pd single-site catalysts(SSCs)have great potential.Herein,two Pd SSCs with different coordination structures are prepared on hierarchical nitrogen-doped carbon nanocages(hNCNC)by regulating the nitrogen species with or without using dicyandiamide.With using dicyandiamide,the obtained Pd1-Ndicy/hNCNC SSC features the coordinated Pd by two pyridinic N and two pyrrolic N(PdN^(py)_(2)N^(pr)_(2)).Without using dicyandiamide,the obtained Pd1/hNCNC SSC features the coordinated Pd by pyridinic N and C(PdN^(py_(x)C_(4-x)),x=1-4).The former exhibits an 18-fold increase in catalytic activity compared to the latter.Theoretical results reveal the abundant unoccupied orbital states above the Fermi level of moiety,which can facilitate the activation of substrate molecules and dynamics of acetylene hydrogenation as supported by the combined theoretical and experimental results.In addition,PdN^(py)_(2)N^(pr)_(2)the moiety presents a favorable desorption of ethylene.Consequently,the Pd1-Ndicy/hNCNC SSC exhibits high C2H2 conversion(99%)and C2H4 selectivity(87%)at 160℃.This study demonstrates the impact of Pd single-site coordination structure on catalytic performance,which is significant for the rational design of advanced Pd SSCs on carbon-based supports.

关 键 词：coordination structure hierarchical nitrogen-doped carbon nanocages PALLADIUM semihydrogenation of acetylene singlesite catalysts 

分 类 号：O64[理学—物理化学]