Support Effects on the Activity of Ni Catalysts for the Propane Steam Reforming Reaction.

The catalytic performance of supported Ni catalysts for the propane steam reforming reaction was investigated with respect to the nature of the support. It was found that Ni is much more active when supported on ZrO or YSZ compared to TiO, whereas AlO and CeO-supported catalysts exhibit intermediate performance. The turnover frequency (TOF) of CH conversion increases by more than one order of magnitude in the order Ni/TiO < Ni/CeO < Ni/AlO < Ni/YSZ < Ni/ZrO, accompanied by a parallel increase of the selectivity toward the intermediate methane produced. In situ FTIR experiments indicate that CH species produced via the dissociative adsorption of propane are the key reaction intermediates, with their hydrogenation to CH and/or conversion to formates and, eventually, to CO, being favored over the most active Ni/ZrO catalyst. Long term stability test showed that Ni/ZrO exhibits excellent stability for more than 30 h on stream and thus, it can be considered as a suitable catalyst for the production of H via propane steam reforming.