Ni/CeO2 promoted Ru and Pt supported on FeCrAl gauze for cycling methane catalytic partial oxidation—CPOX

Abstract

Stranded natural gas is economically unattractive due to high operating and investment costs of conventional technologies necessary to bring it to market. However, milli-second reactors operating at a GHSV up to 200 000 h−1 reduce investment. The first step of a gas-to-liquids process produces syngas—a mixture of CO and H2. Here, we propose promoted Ni-based catalysts supported on FeCrAl knitted gauze to partially oxidize CH4 in air to syngas. High syngas selectivities at 1 bar, 700 °C and CH4/O2 ratios of 2.5 to 5 suggests an apparent direct reaction path to CO and H2. Ru promoted catalysts had higher turnover rates in CH4 activation compared to Ni, Ni-Pt and Ni-Pt-Ru. All catalysts containing Pt formed carbon species refractory to air regeneration at 700 °C. 2.25% Ni with 0.1% Ru had the highest CH4 turnover rate (155 mol s−1 mol−1) and CO selectivity (80%) at a CH4/O2 ratio 2.5. CH4 conversion and CO production were constant after 50 reaction-regeneration cycles that dosed the catalyst for 25 min with methane/air followed by an equal time in air at the same reaction temperature.