A series of catalysts were prepared by calcination of copper(Ⅱ) hydroxide and pseudo boehmite with a Cu/Al molar ratio of 1/2.When the calcination temperature was raised from 500 ℃ to 900 ℃,the main component of the catalysts varied from CuO to CuAl2O4,and the catalyst surface area declined from 75.0 to 16.6 m2/g.The catalysts,with CuAl2O4 as main component and high surface area,showed excellent catalytic performance in methanol steam reforming reaction (MSR).In addition,the catalyst,with CuAl2O4 as main component,had the copper releasing as well as sintering,hence the catalytic activity increased first and then decreased.The preferred catalyst was calcined at 800 ℃ and had better catalytic performance than commercial Cu-Zn-Al.Meanwhile,this catalyst can be regenerated after MSR.When the catalyst was not pre-reduced,the methanol conversion was 55.2％ at the beginning,and then increased to 79.3％ at 288.3 h,and decreased to 63.9％ at 1 000.5 h,when reaction conditions were the molar ratio of alcohol to water 1,240 ℃,1.0×106 Pa,WHSV of 1.75 h-1.%以氢氧化铜和拟薄水铝石为原料(Cu/Al物质的量比为1/2),采用固相法经过不同温度焙烧后获得了一系列Cu-Al 氧化物催化剂.当焙烧温度由500℃提高到900℃时,催化剂的主要铜物种由CuO渐变为CuAl2O4,比表面积由75.0 m2/g降低至16.6 m2/g.在甲醇重整反应过程中,以CuAl2O4为主要成分且具有较高比表面积的催化剂表现了优异的催化性能.另外,以CuAl2O4为主要成分的催化剂不经过预还原处理时,在反应过程中同时存在活性铜的释放和烧结,其催化活性呈现先增加后降低的趋势.在本研究催化剂制备条件下,优选800℃焙烧的催化剂,其催化性能优于商业Cu-Zn-Al催化剂,且具有可再生性.当催化剂不经过预还原处理时,在水醇物质的量比为1、240℃、1.01×106 Pa、质量空速为1.75 h-1的条件下,甲醇起始转化率为55.2％;反应进行288.3 h时,甲醇转化率升高至79.3％;反应继续运行至1 000.5 h时,甲醇转化率降低至63.9％.
展开▼
