钯基乙炔选择性加氢催化剂研究进展

催化选择加氢去除乙烯中微量乙炔是石化工业重要的反应过程，工业钯基催化剂选择性低、催化剂使用寿命较短。本文综述了近年来国内外乙炔选择性加氢钯基催化剂的研究进展。主要探讨了过渡金属、金属氧化物与非金属配体助剂能调变钯粒子空间结构，隔离分散钯粒子并与钯粒子产生电子效应；阐明了钯粒子尺寸与织构形貌的调控能改变钯的晶面结构，影响钯对乙烯的吸脱附和对氢气的活化与解离性能；评述了单一氧化物、复合金属氧化物、碳材料等载体为催化剂提供合适的表面酸碱性并加强了与活性中心之间的相互作用，稳定钯粒子抑制其发生迁移与团聚。提高乙烯选择性与催化剂稳定性是该研究的重点与难点，负载型钯基催化剂的发展方向是构建高分散钯粒子，并在反应过程中保持稳定。

Research progress in palladium-based catalysts for selective hydrogenation of acetylene

The selective hydrogenation of ethyne in an ethene-rich stream is a critical process in petrochemical industry. Supported palladium catalysts are generally used as the semi-hydrogenation catalysts. However， several problems still exist， including poor selectivity and short catalyst lifetime. This paper reviews recent researches of the palladium-based catalysts applied in selective hydrogenation of acetylene. The transition metals， metallic oxides and nonmetallic ligands can enhance the selectivity of ethylene by modifying the structure of the active sites， isolating the palladium nanoparticles and forming electron-transport between palladium particles and promoters. The particle size and texture of palladium determine the adsorption/desorption of ethylene and the activation/dissociation of hydrogen. In addition，the supports，such as single oxides，mixed metal oxides and carbon materials can provide appropriate surface acidity and basicity and strengthen the interaction between the supports and metals to prevent the palladium nanoparticles from migration and aggregation. Improving the selectivity of ethylene and stability of catalysts the key and difficult point in this field. The developing tendency of the supported palladium catalyst is to prepare highly dispersed palladium particles and to keep them stable in the reaction process.