Fuel Processing Technology, Vol.92, No.10, 1868-1875, 2011
Methane reforming reaction with carbon dioxide over SBA-15 supported Ni-Mo bimetallic catalysts
A series of mesoporous molecular sieves SBA-15 supported Ni-Mo bimetallic catalysts (xMo1Ni, Ni = 12 wt.%, Mo/Ni atomic ratio = x,x = 0, 0.3, 0.5, 0.7) were prepared using co-impregnation method for carbon dioxide reforming of methane. The catalytic performance of these catalysts was investigated at 800 C, atmospheric pressure, GHSV of 4000 ml.g(cat)(-1).h(-1) and a V(CH4)/(CO2) ratio of 1 without dilute gas. The result indicated that the Ni-Mo bimetallic catalysts had a little lower initial activity compared with Ni monometallic catalyst, but it kept very stable performance under the reaction conditions. In addition, the Ni-Mo bimetallic catalyst with Mo/Ni atomic ratio of 0.5 showed high activity, superior stability and the lowest carbon deposition rate (0.00073g(c).g(cat)(-1).h(-1))in 600-h time on stream. The catalysts were characterized by power X-ray diffraction, N-2-physisorption, H-2-TPR, CO2-TPD,TG and TEM. The results indicate that the Ni-Mo bimetallic catalysts have smaller metal particle, higher metal dispersion, stronger basicity, metal-support interaction and Mo2C species. It is concluded that Mo species in the Ni-Mo bimetallic catalysts play important roles in reducing effectively the amount of carbon deposition, especially the amount of shell-like carbon deposition. (C) 2011 Elsevier B.V. All rights reserved.