Non-thermal plasma-assisted steam methane reforming for electrically-driven hydrogen production

Plasma-assisted steam methane reforming (SMR) has become a promising approach for low temperature and small-scale hydrogen production. To increase H2 yields, water-gas-shift reactions are needed to drive the formed CO to CO2 and H2. In this study, bulk gas temperature, plasma power and water feed rate strongly impacted the CO and CO2 product selectivity at high methane conversions of 60-80% in the presence of a Ni-based catalyst. CO2-enriched hydrogen could be formed directly with H2O/methane ratios > 4. To further increase the CO2/CO product selectivity, a "one-pot" cascade design with a Cu/ZnO/Al2O3/MgO catalyst bed placed downstream of the plasma zone achieved substantially higher CO2/CO selectivity (>15) in the effluent gas at 60% methane conversion and 300 degrees C. Comparably, placing the Cu-based catalyst in the plasma zone does not alter the CO2/CO selectivity. This study highlights the use of plasma reactor systems to directly tune the catalytic SMR perfor-mance and lead to an electrified route for hydrogen production.