Suniight in Your Tank—Right Away

摘要

Using sunlight to split water and generate hydrogen doesn't make the most useful chemical fuel. To use hydrogen on a large scale, societies would have to develop a new infrastructure to store, transport, and distribute the energy carrier. With that limitation in mind, some researchers are looking to use artificial photosynthesis to generate hydrocarbon fuels like those we already burn. Their goal is essentially to run combustion in reverse, starting with carbon dioxide (CO,) and water and using the energy in sunlight to knit the chemical bonds needed to make hydrocarbons, such as gaseous methane and liquid methanot. "That's a technology that's going to come," says Harry Gray, a chemist at the California Institute of Technology in Pasadena. "But it is hard."