Adsorption Behavior and Electron Structure Engineering of Pd-IL Catalysts for Selective Hydrogenation of Acetylene

Abstract

Developing the catalytic activity and selectivity of palladium (Pd) catalysts for acetylene hydrogenation is key importance in the chemical industry and remains a challenge to this day. Here, the catalytic performance of Pd catalysts are influenced by the Pd electronic structure, in turn, controlled by different heteroatom doped support. Different catalysts are prepared by ionic liquids (ILs) with different precursors, and catalytic activity of selective hydrogenation of acetylene was investigated. The Pd/NC catalyst exhibits extraordinary conversion, selectivity and stable for the hydrogenation of acetylene (94.6% acetylene conversion with 91.3% selectivity to ethylene). This remarkable catalytic performance of Pd/NC is mainly linked to nitrogen-doped (N-doped) changes the electronic structure of Pd nanoparticles, ensures the rapid desorption of ethylene and prevents the formation of unnecessary ethane by over hydrogenation (demonstrated by XPS and DFT). Our strategy of controlling the electronic structure of Pd can be widely used in the reactions that change the micro electrochemical properties of active metals. The selective hydrogenation of acetylene to ethylene over Pd/NC with excellent conversion and selectivity is investigated. The doping of nitrogen leads to the unique electronic structure of Pd on the Pd/NC catalyst, which influences the adsorption of ethylene and acetylene, thus promoting its catalytic activity.