Aqueous-phase reforming of ethylene glycol on silica-supported metal catalysts

Reaction kinetic studies were conducted for aqueous-phase reforming of ethylene glycol over silica-supported Ni, Pd, Pt, Ru, Rh and Ir catalysts at temperatures of 483 and 498 K and at a total pressure of 22 bar. The rates of production of hydrogen, carbon dioxide, carbon monoxide, methane, ethane and higher paraffins were measured for conversion of an aqueous feed solution containing 10 wt.% ethylene glycol. It was observed that the overall catalytic activity for ethylene glycol reforming, as measured by the rate of CO2 production at 483 K, decreases in the following order for silica-supported metals: Pt∼Ni>Ru>Rh∼Pd>Ir. Silica supported Rh, Ru and Ni showed a low selectivity for production of H2 and a high selectivity for alkane production. In addition, Ni/SiO2 showed significant deactivation at the higher temperature of 498 K. Silica-supported Pt and Pd catalysts exhibited relatively high selectivities for production of H2, with low rates of alkane production. It appears that catalysts based on Pt and Pd may be promising materials for the selective production of hydrogen by aqueous-phase reforming of oxygenated hydrocarbons, such as ethylene glycol.