Methanol steam reforming over CuZnAl catalysts derived from hydrotalcite precursor I. Effect of calcination temperature

作者：Tang Ying^*; Liu Ye; Lu Yong; Zhu Ping; He Mingyuan

来源：Chinese Journal of Catalysis, 2006, 27(10): 857-862.

• copper oxide
• zinc oxide
• alumina
• hydrotalcite
• methanol
• hydrogen
• steam reforming
• fuel cell

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 degrees C showed excellent activity and stability for the methanol steam reforming at 250 degrees C 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 degrees C to form nanosized CuO and the CuAl2O4 spinet 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 degrees C led to severe sintering of CuO and facilitated the formation of the CuAl2O4 spinet phase, causing a significant decrease in the number of active sites. With lower calcination temperatures (300-500 degrees C) the hydrotalcite precursor was incompletely decomposed to form a (Cu,Zn)AlxOy(CO3)(z) composite and the associated CuAl2O4 spinet phase was not found. This resulted in the sintering of metallic Cu and ZnO as well during the reaction, thereby decreasing the catalyst activity.

• 出版日期2006-10
• 单位华东师范大学