中文摘要：

以类层柱CuZnAl水滑石为前体，经不同温度焙烧制备了一系列甲醇水蒸气重整制氢催化剂．在250℃、水／甲醇比1．3和重时空速2．5h^-1下的反应结果表明，600℃焙烧的催化剂具有优异的活性和稳定性，而≤500℃和≥700℃焙烧后的催化剂活性较差．热重、X射线衍射、傅里叶变换红外光谱和程序升温还原分析结果表明，600℃焙烧时水滑石分解较为完全，析出纳米CuO粒子的同时伴生CuAh04尖晶石相，进而在反应过程中对金属Cu纳米粒子和ZnO起到良好的隔离和稳定作用．焙烧温度≥700℃时CuO纳米粒子发生二次团聚，同时CuAl2O4尖晶石相大量生成，造成催化活性位减少，活性较低；而焙烧温度≤500℃时水滑石分解不完全，生成（Cu，Zn）AlxOy（CO3）z复合物且无尖晶石相伴生，造成反应中金属Cu纳米粒子和ZnO聚集，导致催化剂活性较低．

英文摘要：

A series of CuZnAl composite oxide catalysts were prepared by calcination of the CuZnAl hydrotalcite precursor at various temperatures and used in the methanol steam reforming reaction, The catalyst calcined at 600 ℃ showed excellent activity and stability for the methanol steam reforming at 250 ℃ and WHSV of 2.5 h^- 1 with a H2O/CH3OH molar ratio of 1.3 as compared to those calcined at lower or higher temperatures. The results of thermogravimetry, X-ray diffraction, Fourier transform infrared spectroscopy, and temperature-programmed reduction revealed that CuZnAl hydrotalcite was almost completely decomposed at 600 ℃ to form nanosized CuO and the CuAl2O4 spinel phase that played a key role in separating and stabilizing the nanosized Cu and ZnO during the reaction. Increasing the calcination temperature to over 700 ℃ led to severe sintering of CuO and facilitated the formation of the CuAl2O4 spinel phase, causing a significant decrease in the number of active sites. With lower calcination temperatures （300-500℃ ）, the hydrotalcite precursor was incompletely decomposed to form a （Cu, Zn）AlxOy （CO3）z composite and the associated CuAl2O4 spinel phase was not found. This resulted in the sintering of metallic Cu and ZnO as well during the reaction, thereby decreasing the catalyst activity.