Modulation of species adsorption to promote the semi-hydrogenation of C2H2 to C2H4 over Ni-based catalysts

Abstract

Nickel-based bimetallic catalysts exhibit excellent ethylene selectivity in acetylene hydrogenation reactions. However, the rational design and control of the interaction between active adsorbates and catalyst surfaces still remains a significant challenge. In this paper, the introduction of the second metals Fe, Co, Mn, and Mo dilutes the catalyst surface and alters the electronic properties of Ni. As a result of the geometric and electronic dual modulation between the bimetals, ethylene is adsorbed on the catalyst surface through weak π-bonds, which accelerates the desorption of ethylene. In addition, alloying a second metal in Ni significantly lowers the desorption energy of ethylene compared to the hydrogenation barrier, which improves the selectivity of the reaction, and the experimental findings further confirm the validity of the calculations. This work offering a new strategy to the development Ni-based bimetallic catalysts by modulating the strength of adsorbed species on the catalyst surface to attain superior catalytic performance in hydrogenation reactions.