Light-driven reaction converts carbon dioxide into fuel and feedstock

One of the problems with carbon dioxide is the strength of the carbon-oxygen bond. Potentially, CO₂ in the atmosphere could be a valuable source of carbon for industrial processes, which would both reduce its concentration and cut raw material costs. Unfortunately, the CO₂ molecule is so stable that it's very difficult to break its bonds and free up the carbon for reactive chemistry.

CO₂ activation – the process of persuading oxygen-bound carbon to react – has therefore been a goal of chemistry for some years. A potential breakthrough has now come from researchers at Duke University in North Carolina, US, who have engineered nanoparticles containing the precious metal rhodium that convert CO₂ into methane; another very stable carbon compound but one that can be more easily persuaded to react. The methane could be used directly as a fuel or as a feedstock for reaction into further organic molecules.

Rhodium has been known as a useful catalyst for organic reactions for many years, and is generally used by heating it. However, over the past two decades researchers have been looking at a field known as plasmonics, which is concerned with the way that metal nanoparticles behave when struck by light.