In what some are calling a major breakthrough for renewable energy, MIT chemists Daniel Nocera and Matthew Kanan discover a new catalyst that speeds up the splitting of water into oxygen and hydrogen. The discovery may heighten interest in pollution-free fuel cell vehicles, which generate energy by combining hydrogen and oxygen chemically, emitting only water. The catalyst, made from cheap materials and working in ordinary water, may also make it easier to convert sunlight into chemical fuels, storing solar energy in much the way plants do.