Copper-zinc-aluminum hydrotalcite precursors with different molar ratios of Cu/Zn were prepared by co-precipitation method,pretreated with acetylene and reduced in-situ with hydrogen after calcination.Then CumZn3-mAl-LDO(T140-R150)catalysts(m=1,1.5,2,3)were obtained,and further characterized by N2 physical adsorption,X-ray diffraction,scanning electron microscopy and transmission electron microscopy,which aims to investigate their catalytic performance in the selective hydrogenation of acetylene in the presence of a large amount of ethylene.The results show that the dispersion of copper in precursors can be improved by introducing zinc into Cu-Al hydrotalcite,which is beneficial to the formation of CuxC hydrogenation active phase,and improve the performance of selective hydrogenation of acetylene.The optimal preparation conditions of the catalyst are as follows:Cu/Zn molar ratio of 1,acetylene treatment temperature of 140 ℃,acetylene treatment time of 2 h,hydrogen reduction temperature of 150 ℃,and hydrogen reduction time of 3 h.At temperature of 100 ℃ and atmospheric pressure,the acetylene conversion of the Cu1.5Zn1.5Al-LDO(T140-R150)catalyst can reach 100％;the ethene selectivity,C4 selectivity and ethane selectivity is 53.9％,15.5％and 30.6％respectively.
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