Synergistic effect between amorphous ZrO2 modified support and Pd catalyst: Unveiling superlative sulfur resistance and exquisite catalytic hydrogenation performance

Abstract

The presence of sulfides in the reaction system can seriously affect the stability and activity of the catalysts. In this paper, we compare the impact of introducing varying amounts of the metal oxide ZrO2 on the hydrogenation activity and sulfur resistance of Pd-based catalysts. The study examined the effect of calcination temperature for catalysts and various organic sulfide types on their catalytic performance. We employed multiple techniques to characterize the catalysts, including physical adsorption, TEM, XRD, XPS, H2-TPD, NH3-TPD, and Py-IR. The results revealed that the catalysts achieved 99.9 % conversion and exhibited 99.5 % selectivity towards 4-ethyltoluene when the Pd and Zr molar ratio was 1:5. Furthermore, they could withstand the presence of toxicants for over 10 cycles. The main reason for the difference in activity and stability between catalysts lies in introducing ZrO2 as a promoter. This introduction increases the number of acidic sites and enhances the electronic effect, thereby facilitating the cleavage of H2 by Pd0. The synergistic effect between Pd and ZrO2 decreases the strength of S-Me, impedes sulfide adsorption, and improves the sulfur resistance stability of the catalyst. This work demonstrates that ZrO2-modified Pd-based catalysts have great potential in the anti-sulfur system of olefin hydrogenation.