The University of Cambridge demonstrated that it can directly produce the gas—called syngas—sustainably and simply. They used an ‘artificial leaf’ (a silicon-based device that uses solar energy to split hydrogen and oxygen in water) powered by sunlight to accomplish this.
Inspired by photosynthesis two light absorbers, on the artificial leaf, act as molecules in plants that harvest sunlight is combined with a catalyst made from the naturally abundant element cobalt. When the artificial leaf is submerged in water, one light absorber uses the catalyst to produce oxygen. The other carries out the chemical reaction that reduces carbon dioxide and water into carbon monoxide and hydrogen, forming the syngas mixture.
Syngas is commonly used in fuels, pharmaceuticals, plastics and fertilisers. As an added bonus, the researchers discovered that their light absorbers work even under the low levels of sunlight on a rainy or overcast day. This opens up the technology to anywhere in the world and can be used from dawn to dusk.
Professor Erwin Reisner from Cambridge’s Department of Chemistry says the development of synthetic petrol is vital, as electricity can currently only satisfy about 25% of our total global energy demand. “There is a major demand for liquid fuels to power heavy transport, shipping and aviation sustainably”.