Pd-M(M=Fe,Co,Ni)均匀合金催化剂的构筑及表界面调控对苯乙炔选择性加氢性能影响机制研究

苯乙炔选择性加氢是去除苯乙烯中苯乙炔杂质最有效的方法。针对Pd基催化剂在该反应中迄今仍面临原子利用率不高、选择性低、稳定性差及反应机理不明确等问题。本项目拟使用非贵金属铁系元素对Pd活性位点进行改性修饰，通过配位化学合成策略克服双金属的热力学不混溶性，制备化学有序的均匀双金属合金Pd-M（M=Fe,Co,Ni）；同时通过调整金属比例、粒径大小、氮杂碳载体选择和负载方式等进一步实现Pd活性位点的隔离分散及表界面调控，构筑高性能的苯乙炔选择性加氢催化剂。进而结合催化性能测试、材料表征和密度泛函理论计算，研究催化剂化学组成、尺寸效应和表界面调控对催化活性、选择性和稳定性的影响规律；并通过Pd-M双金属均匀合金与异质合金催化剂结构和催化性能的对比，深入系统地探究催化构效关系和苯乙炔选择性加氢反应机理。本项目的开展将为新型Pd基选择性加氢催化剂的开发提供一定的理论依据和研究基础。

Selective hydrogenation of phenylacetylene is the most effective method to remove phenylacetylene impurities in styrene. So far, Pd based catalysts still face the problems of low atomic utilization, low selectivity, poor stability and unclear reaction mechanism. This project aims to modify the Pd active sites with the non-noble iron series elements, and to prepare homogeneous bimetallic Pd-M (M=Fe, Co, Ni) alloys with ordered structures by overcoming the thermodynamic immiscibility in bimetallic systems using coordination chemical synthesis strategy. Then through adjusting the metal proportions, particle sizes, selection of nitrogen doped carbon supports and loading methods, the isolation/dispersion and surface/interface regulation of Pd active sites could be realized. Thus, catalysts of high performance for the selective hydrogenation of phenylacetylene can be constructed. Combining the characterization of the samples and experimental results with density functional theory calculation, the influences of chemical constitution, size effect and surface/interface regulation on the activity, selectivity and stability of the catalysts will be studied. By comparing with the structures and catalytic effects of Pd-M bimetallic homogeneous alloy with heterogeneous alloy catalysts, the structure-activity correlations and the selective phenylacetylene hydrogenation mechanism would be systematically investigated. This research will provide certain theoretical foundation and research basis for the development of new Pd-based selective hydrogenation catalysts.