Regulating metal-support interactions of Pd/MgAl2O4 for efficient selective hydrogenation of acetylene

Abstract

Selective hydrogenation of a trace amount of acetylene to ethylene is a green and economical process to purify the ethylene stream in the olefin industry. Pd-based catalysts are widely explored for this process due to their excellent H2 and C2H2 activation abilities. However, the strong adsorption of C2H4 on metallic Pd sites often leads to the undesired over-hydrogenation product (i.e., ethane). Herein, we fabricated Pd/MgAl2O4 catalysts with tunable metal-support interactions by changing calcination temperatures to efficiently modify the electronic structure of Pd species. The Pd/MgAl2O4 with the optimized calcination temperature exhibits 96 % acetylene conversion and enhanced ethylene selectivity of 87 % due to weak adsorption of intermediates at 120 ℃, and shows excellent stability with negligible activity decay during a 50 h test. This work provides a strategy for designing catalysts with regulated metal-support interactions for selective hydrogenation processes.