The effect of pressure on CO2 reforming of methane and the carbon deposition route using noble metal catalysts

Dry reforming of methane and 13 C-labeled methane were studied over Pt/ZrO 2 , Pt/Ce-ZrO 2 , and 1%wtRh/Al 2 O 3 at several pressures. It appears that carbon deposited on the catalysts resulted from both methane and CO 2 The presence of approximately equal ratios of 13 C- and 12 C-containing products suggests that the oxygen exchange reaction between CO and CO 2 is very fast. Temperature-programmed oxidation of carbon formed on the catalysts indicates that CO disproportionation contributes significantly to carbon deposition at lower and higher pressures. The Rh/alumina supported catalyst is the most resistant toward carbon deposition both at lower and higher pressures. In all catalysts, methane and CO 2 conversions as well as H 2 /CO ratios decreased with increasing pressure.