Perovskite-type Oxide Of La_1-xCe_xCo_0.7Cu_0.3O₃ Supported On Zirconia For Ethanol Synthesis From Syngas

Cu-Co based catalyst is promising for ethanol synthesis（ES）,where the synergy between copper and cobalt is critical,and to improve the catalytic performance,promoters are important.In this work,a new scheme was proposed to intensify the interaction between copper with cobalt and between Cu-Co with the promoters,namely,the ions of copper,cobalt,lanthanum and cerium were confined into La_1-xCe_xCo_0.7Cu_0.3O₃（x=0,0.05,0.15）with perovskite structure and were supported on zirconia.These catalysts were prepared by impregnation method and used for ES from syngas and were characterized by using BET,XRD,XPS,TEM,TG and CO-TPD techniques.Among these catalysts,La_0.95Ce_0.05Co_0.7Cu_0.3O₃/ZrO₂ showed very good catalytic performance with selectivity to total alcohols higher than 60%and selectivity to ethanol about 50%in the total alcohols.Then,La_0.95Ce_0.05Co_0.7Cu_0.3O₃/Zr O₂ was used in the stability test.In the 1000hours’stability test,the catalyst exhibited very good stability in the last 500 h and a continuous rise in the selectivity to alcohols.La_0.95Ce_0.05Co_0.7Cu_0.3O₃/ZrO₂ under different treatments were characterized by using XRD,TG,BET,XPS,ICP-MS and TEM techniques.After reduction,clusters composed of Cu-Co alloy nanoparticles,ceria and lanthanum oxide was formed and loaded on zirconia.Investigation on the variation of the catalyst structure with reaction time showed that with the reaction going on,the clusters spread over the surface of Zr O₂ and at last,all the clusters fused together to form a membrane loaded on the Zr O₂ and the whole catalyst was covered by a membrane-like coating formed by Co₂C.The characterization results showed that the carbondepositionwasthemainreasonforthedeactivationof La0.95Ce0.05Co0.7Cu0.3O3/ZrO2 catalyst.This catalyst design scheme could be extended for preparing a lot of catalyst for many reactions.