低负载大孔Pd/α-Al_2O_3活性组分分布对CO偶联反应的影响  

Effects of Pd distribution in macro-porous α-Al_2O_3 support on CO coupling reaction

作　　者：沈普霖 罗漫[1] 肖文德[1] 

机构地区：[1]上海交通大学化学化工学院,上海200240

出　　处：《天然气化工—C1化学与化工》2015年第3期1-3,9,共4页Natural Gas Chemical Industry

摘　　要：在平均孔径为2.799×103nm的α-Al2O3载体上负载金属钯,制备贵金属负载型催化剂Pd/α-Al2O3。调节前驱体浸渍液的p H,在p H为1.67时,得到分散在整个载体中的均匀分布Pd/α-Al2O3催化剂;在p H为12.25时,可以制备只负载在氧化铝载体表面以下约40μm的蛋壳型分布Pd/α-Al2O3催化剂。催化表征结果显示不同分布的催化剂钯晶粒的粒径均在2nm^3nm左右,属于高度分散状态。在无梯度反应器中,对CO偶联制备草酸二甲酯(DMO)这一反应进行考评,得出均匀型分布催化剂较蛋壳型结构活性更优的结论。Supported noble metal catalyst Pd/α-Al2O3 was prepared with the α-alumina possessing an average pore size of 2.799 ×10^3nm as support. The uniform Pd distribution and the egg-shelled Pd distribution with a depth of 40μm were obtained by controlling the pH of precursor impregnation solution at 1.67 and 12.25, respectively. Catalyst characterization results showed that the palladium particles size was about 2 nm to 3nm, which were in a highly dispersed state. These catalysts were evaluated through the synthesis of dimethyl oxalate （DMO） by CO coupling method in a no-gradient reactor. It was shown that Pd/α-Al2O3 with uniform Pd distribution generally had higher catalytic activity than the egg-shelled one.

关 键 词：蛋壳型分布 钯 氧化铝 CO偶联 草酸二甲酯 

分 类 号：TQ426[化学工程] O643[理学—物理化学]