Abstracted abstract: Ni5Ga3 catalyzes H2 + CO2 to CH3OH at ambient pressure.
The use of methanol as a fuel and chemical feedstock could become very important in the development of a more sustainable society if methanol could be efficiently obtained from the direct reduction of CO2 using solar-generated hydrogen. If hydrogen production is to be decentralized, small-scale CO2 reduction devices are required that operate at low pressures. Here, we report the discovery of a Ni-Ga catalyst that reduces CO2 to methanol at ambient pressure. The catalyst was identified through a descriptor-based analysis of the process and the use of computational methods to identify Ni-Ga intermetallic compounds as stable candidates with good activity. We synthesized and tested a series of catalysts and found that Ni5Ga3 is particularly active and selective. Comparison with conventional Cu/ZnO/Al2O3 catalysts revealed the same or better methanol synthesis activity, as well as considerably lower production of CO. We suggest that this is a first step towards the development of small-scale low-pressure devices for CO2 reduction to methanol.
Maybe the notion of a large number of small solar installations hydrolyzing water and using a cheap widget to convert the H2 plus a tank of sequestered CO2 to methanol is a little overoptimistic, but it would help solve the solar daily peak energy production surplus and energy storage problems. More generally, anything that lets us do basic chemical transformations with cheap equipment is a win.