固相法合成铜铝尖晶石催化甲醇重整反应

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%.

Cu-Al spinel catalyst prepared by solid phase method for methanol steam reforming

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.