摘要
ZnO-Al2O3 derived from layered double hydroxides （ZnAl-LDH） was successfully applied for dispersion of Pd-Ag bimetallic catalysts for the selective hydrogenation of acetylene to ethylene and the Pd-Ag/ZnO-Al2O3 cata- lyst showed the best catalytic performance among the prepared samples. It was found that the catalyst carrier of ZnO-Al2O3 metal-oxides derived form ZnAl-LDH could significantly suppress the over-hydrogenation of acetylene to obtain the relatively higher selectivity of ethylene. The introduction of Ag restricted efficiently the formation of coke because of the oligomerization reaction, which was further evidenced by thermal gravimetric analysis. The se- lectivity towards ethylene was in the order of Pd-Ag/ZnO-Al2O3〉Pd/ZnO-Al2O3〉Pd-Ag/Al2O3〉Pd/Al2O3 at a high conversion level. As the thermal gravimetric and differential temperature analysis （TG-DTA） revealed, Pd-Ag intermetallic catalyst on the ZnO-Al2O3 support showed less coke formation.
ZnO-Al2O3 derived from layered double hydroxides （ZnAl-LDH） was successfully applied for dispersion of Pd-Ag bimetallic catalysts for the selective hydrogenation of acetylene to ethylene and the Pd-Ag/ZnO-Al2O3 cata- lyst showed the best catalytic performance among the prepared samples. It was found that the catalyst carrier of ZnO-Al2O3 metal-oxides derived form ZnAl-LDH could significantly suppress the over-hydrogenation of acetylene to obtain the relatively higher selectivity of ethylene. The introduction of Ag restricted efficiently the formation of coke because of the oligomerization reaction, which was further evidenced by thermal gravimetric analysis. The se- lectivity towards ethylene was in the order of Pd-Ag/ZnO-Al2O3〉Pd/ZnO-Al2O3〉Pd-Ag/Al2O3〉Pd/Al2O3 at a high conversion level. As the thermal gravimetric and differential temperature analysis （TG-DTA） revealed, Pd-Ag intermetallic catalyst on the ZnO-Al2O3 support showed less coke formation.
基金
This work was supported by the National Natural Science Foundation of China （21476145）. The authors thank Y. F. Liu, Z. L. Guo, L. M. Li, and C. Y. ki for useful discussion and helps. X. P. Gao thanks the China Cheng Da Engineering Co., Ltd for scholarship.
