C2H2 Selective Hydrogenation to C2H4: Engineering the Surface Structure of Pd-Based Alloy Catalysts to Adjust the Catalytic Performance

The surface structure of the catalyst is a key factor to affect its catalytic performance toward the targeted reaction. In this work, aiming at revealing the surface structure influences of Pd-based alloy catalysts on the catalytic performance of C2H2 selective hydrogenation, four kinds of surface structures of Pd-based alloy catalysts, including the core-shell Pd-nL@M (M = Cu and Ag), the core-shell Pd-nL@PdxMy, the uniform alloy Pd1Cu3 and Pd1Ag1, and the subsurface structure Pd-1L-M-sub are engineered, and the corresponding catalytic performance is fully examined using DFT calculations. Our results reveal that the catalytic performance of C2H2 selective hydrogenation is closely related to the surface structures of Pd-based alloy catalysts; among them, the Pd1Cu3, Pd-1L-Cu-sub, Pd1Ag1, and Pd-1L-Ag-sub catalysts are screened out to serve as four promising candidates in the hydrogenation process, which exhibit better activity and selectivity toward gaseous C2H4 formation, especially, Pd1Cu3 and Pd1Ag1 with the uniform alloy structure. However, in the polymerization process, both Pd-1L-Cu-sub and Pd-1L-Ag-sub catalysts are deactivated due to the easier production of green oil, whereas both Pd1Cu3 and Pd1Ag1 catalysts effectively inhibit green oil production and present excellent thermal stability due to their ordered atomic arrangement. This work indicates the importance of rationally engineering the surface structure of Pd-based alloy catalysts, which may be applied to the design of other catalysts in C2H2 selective hydrogenation.

Automated summary

This study investigates the catalytic performance of Pd-based alloy catalysts with different surface structures, and identifies Pd1Cu3 and Pd1Ag1 with uniform alloy structure as promising candidates for C2H2 selective hydrogenation due to their better activity and selectivity. The results highlight the importance of rational engineering of surface structure in designing effective catalysts for C2H2 selective hydrogenation.