A pair of catalysts can oxidize alcohols electrochemically in a relatively efficient and speedy manner. Such a catalyst system could find use in fuel cells powered by biomass. Organic alcohols are abundant in biomass derived from trees and other plants, and fuel cells could generate electricity by oxidizing such alcohols electrochemically. TEMPO (2,2,6,6-tetramethyl-1-piperidine N-oxyl) is an effective catalyst for such oxidations, but it requires running fuel cells at high electrode potentials, which is not energy efficient. Shannon S. Stahl and Artavazd Badalyan at the University of Wisconsin, Madison, have now developed a dual electrocatalyst system that overcomes this problem (Nature 2016, DOI: 10.1038/nature18008). They show that (2,2′-bipyridine)Cu(II) and TEMPO work cooperatively as catalytic redox partners in a two-electron oxidation of alcohols. The two-catalyst oxidations run at a more-efficient electrode potential—a reduction of a half-volt—and are nearly fivefold faster, compared with TEMPO-only reactions. Electrocatalysis expert Shelley D. Minteer of the University of Utah says that the next steps toward incorporating the cocatalysts in a fuel cell are demonstrating their long-term stability and that they can be immobilized on surfaces.