IEEE Spectrum has a post about a new discovery out of Stanford University.
Biofuels, once hailed as a planetary savior and alternative to oil and gas, have not quite fulfilled that destiny. Traditional, mass-produced biofuels from crops such as corn carry a litany of problems, including land use issues and questions of life cycle emissions. If we could generate usable fuels from more benign sources, it could go a long way toward solving a host of energy and environmental problems. A team at Stanford University reports today in Nature that they have a novel way to produce ethanol from carbon monoxide (CO) gas using a metal catalyst made of copper nanocrystals.
“We have discovered the first metal catalyst that can produce appreciable amounts of ethanol from carbon monoxide at room temperature and pressure—a notoriously difficult electrochemical reaction,” said senior study author and Stanford chemistry professor Matthew Kanan in a press release.
Copper is the only material known to electroreduce CO down to generate fuels, but it does so at extremely low efficiencies. Kanan’s group improved this with a nanocrystalline form of copper produced from copper oxide; this new material improves the efficiency of the reactions dramatically.
The researchers built a fuel cell, including a cathode made of the new copper nanocrystals, and suspended it in CO-saturated water; a small voltage applied across the fuel cell generates the resulting ethanol products. The Faraday efficiency using the oxide-derived material was 57 percent, meaning more than half of the current used went toward producing ethanol and acetate. Standard copper particles, meanwhile, produced hydrogen almost exclusively (Faraday efficiency of 96 percent) and very little ethanol.