沉淀温度对CuO/ZnO/Al_2O_3催化剂前驱体物相及催化水煤气变换反应活性的影响  

Influence of Precipitation Temperature on Phase Composition of Precursor of CuO/ZnO/Al_2O_3 Catalyst and Its Catalytic Activity for Water Gas Shift Reaction

作　　者：房德仁[1] 刘中民[2] 杨越[2] 孟霜鹤[2] 索掌怀[1] 陈峰[1] 

机构地区：[1]烟台大学应用催化研究所,山东烟台264005 [2]中国科学院大连化学物理研究所,辽宁大连116023

出　　处：《催化学报》2004年第11期920-924,共5页

摘　　要：用X射线衍射、差热热重测定、程序升温还原、N2 吸附、N2 O滴定和常压微反活性评价技术考察了沉淀温度对CuO/ZnO/Al2 O3 系催化剂及其前驱体的物相和催化水煤气变换反应活性的影响 .结果表明 ,在沉淀温度为 6 0～ 90℃时 ,催化剂前驱体中主要存在Cu2 CO3 (OH) 2 ,(Cu ,Zn) 2 CO3 (OH) 2 和 (Cu ,Zn) 6Al2 (OH) 16CO3 ·4H2 O三种物相 .焙烧后的催化剂样品中形成了较多的CuO ZnO固溶体 ,沉淀温度升高有利于CuO ZnO固溶体的形成及催化剂活性的提高 .水煤气变换反应是一个非结构敏感型反应 .The CuO/ZnO/Al 2O 3 catalyst was prepared by the Cu-Zn-Al ternary co-current coprecipitation method at pH 7. The effect of precipitation temperature on the phase composition of the catalyst precursor was studied by XRD, DTG, TPR, N 2 adsorption and N 2O titration methods. The catalyst activity for the water gas shift reaction (WGSR) was tested in a differential fixed-bed reactor at atmospheric pressure. The results demonstrated that Cu 2CO 3(OH) 2, (Cu,Zn) 2CO 3(OH) 2 and (Cu,Zn) 6Al 2(OH) 16 CO 3·4H 2O were the main phases in the catalyst precursor and the amounts of the latter two phases increased with increasing precipitation temperature. In the calcined catalyst, CuO-ZnO solid solution formed and its amount increased as the precipitation temperature increased. No spinel-like phase of (Cu,Zn)Al 2O 4 was detected by XRD in the calcined catalyst. There was a linear relationship between the low-temperature (200 ℃) catalytic activity for WGSR and the Cu surface area of the catalyst. WGSR was a structure-insensitive reaction.

关 键 词：氧化铜 氧化锌 氧化铝 混合氧化物催化剂 前驱体 物相 一氧化碳 水煤气变换反应 

分 类 号：O643[理学—物理化学]