Keywords: supported molecular catalysts, dehydrogenation
Summary:Hydrogen is produced industrially via catalytic steam reforming of nonrenewable methane at temperatures of 400-1000 °C and at steam partial pressures near 30 bar. Hydrogen production from renewable biomass is challenging due to sluggish catalytic rates in water (the most common biomass contaminant), and catalyst deactivation. Furthermore, hydrogen transportation and storage present safety issues that could be addressed using a carrier which releases hydrogen on demand, such as biomass-derived methanol, ethanol, or formic acid, all of which are compatible with direct alcohol fuel cell technologies. The state-of-the-art for sustainable, environmentally benign methanol and ethanol production typically employs biomass (e.g., cellulose) fermentation to “bioalcohols” having ~10% alcohol in aqueous solution. In this report I describe a molecularly designed heterogeneous catalytic system for base- and additive-free methanol and ethanol reforming that operates under mild conditions (40 - 90 °C and 1 atm) with an inexpensive supported Mo catalyst that is air- and moisture- stable. Additionally, this system is active for aqueous alcohols, exhibits no deactivation over days under these conditions, and is selective towards valuable aldehydes with negligible production of greenhouse gases or fuel cell poisons (CO2 or CO), conforming to requirements for formaldehyde production and direct alcohol fuel cell applications.