Dry reforming of methane over Co-Ce-M/AC-N catalyst: Effect of promoters (Ca and Mg) and preparation method on catalytic activity and stability

The catalytic activity of DRM reaction over 1M-1Co-1Ce/AC-N (M = Ca and Mg) catalysts was investigated at 800 degrees C and under atmospheric pressure. By promoting N-doped activated carbon supported Co-Ce catalysts with alkaline-earth metals to obtain catalysts with better catalytic performance is the main purpose of study. The catalysts were prepared by wet-impregnation method and the influence of impregnation sequence on catalytic performance was also studied. The characterization was conducted using TPR, TPD, XPS, TEM and Raman. The catalyst 1Ca-1Co-1Ce/AC-N promoted with Ca and prepared by coimpregnation exhibited higher catalytic activity than unmodified. This was mainly due to the stronger interaction between metal and support as well as better active metals dispersion. The 1Ca-1Co-1Ce/AC-N catalysts also displayed excellent stability and XPS results indicated that higher Ce3+/Ce4+ and O-beta(O-alpha+O-beta) ratios were observed on this catalyst. However, the catalyst 1Co-1Ce/1Ca/AC-N prepared with sequential impregnation exhibited poor stability. In addition, the TEM of the spent catalysts revealed that there were a large number of carbons were generated on active metal surface. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.