New Oxygen-Evolving Catalyst Unveiled

As part of an effort aimed at capturing the power of the sun to meet global energy needs, Daniel G. Nocera and coworkers at Massachusetts Institute of Technology have announced the discovery of a nickel-borate catalyst that improves on the electrochemical splitting of water. (Proc. Natl. Acad. Sci. USA, DOI: 10.1073/pnas.1001859107). Many scientists are developing catalysts that efficiently split water into hydrogen and oxygen, with the idea of using the hydrogen to power fuel cells. Nocera’s group previously reported a low-cost cobalt phosphate catalyst that it prepared as a thin-film electrode for the more difficult oxygen-producing half of the water-splitting process (C&EN, Aug. 4, 2008, page 7). In the new report, Nocera, Mircea Dinc˘a, and Yogesh Surendranath describe electrodepositing thin films of the nickel-based catalyst on a conductive glass substrate from a dilute solution of Ni²⁺ and a borate electrolyte. They note that the new catalyst is even less expensive and as efficient than its cobalt predecessor. The nickel-borate catalyst demonstrates that the cobalt original is not a unique, anomalous material, Nocera says. He adds that it also suggests that there might eventually be a family of related catalysts that researchers will be able to draw from to develop widely available storage technology for solar energy.