SOLAR-FUEL GENERATION Towards practical implementation

The latest advances in solar-fuel generation were the focus of the 'Advanced Materials for Solar-Fuel Generation' symposium at the 2011 MRS Fall meeting in Boston. Materials scientists discuss the most viable approaches to produce high-energy-density fuels from sunlight that can be implemented in existing infrastructures. In the first approach, solar energy is harvested as electricity and when present in surplus amounts used to hydrogenate CO 2 in an electrolyser-type unit. The aim is to produce fuels with higher energy density. Nørskov provided theoretical insights on the reaction mechanism of CO2 reduction and explained why Cu is so far the best suited catalyst for the reaction high selectivity towards hydrocarbons. In the second approach, the electrical wires are entirely eliminated from the device and, as proposed by Heinz Frei, fuels are produced directly from solar light through the formation of electron-hole pairs in a semiconductor catalyst.