Partial Oxidation of Methane on Ni-MgO Catalysts Supported on Metal Foams

The catalytic partial oxidation of methane on Ni-MgO solid solutions supported on metal foams has been studied at temperatures from 600 to 800 (degree)C, 1 atm, 3000-19 000 mL/g-h, CH4/O2 = 2/1. The catalysts were prepared in two ways: (a) oxidized foams were dipped directly into a citrate/ethylene glycol solution containing nitrate precursors and (b) oxidized foams were primed with a bohemite primer and washcoated with Ni-MgO powders, derived from the above solution, in an acidic solution. Results show that the foam-supported catalysts reach near-equilibrium conversions of methane and H2/CO selectivities at the indicated space velocities. Rates of carbon deposition differ greatly among the catalysts, varying from 0.24 mg C/g cat h for the dipped foams to 7.0 mg C/g cat h for the powder-coated foams. Both of these rates are much lower than for the calcined, unsupported powder (57 mg C/g cat h). The results suggest that exposed Cr on all of the foam samples interact with the Ni-MgO catalyst to kinetically limit carbon formation.