Researchers from Tokyo Metropolitan University have developed a way to mount gold nanoparticles on a molecular support known as a polyoxometalate (POM). They successfully applied this to realize nearly 100 percent conversion of carbon monoxide (CO) over a wide temperature range, demonstrating stable performance over long periods of time. They showed how traces of water uniquely contribute to the catalyst’s function, promising insight into catalysis and potential application to exhaust gas and room air purification.