Selective Photoreduction of Carbon Dioxide to Methane in a Polymer Framework

Photoreduction of carbon dioxide (CO₂) has attracted great attentions. Herein, a polymer framework is used to fabricate a micro reaction environment benefit for selective photoreduction of CO₂ to methane (CH₄), with a mixture of platinum and cadmium sulfide as the photocatalyst. In a polymer framework without nitrogen (N) and oxygen (O) sites, carbon monoxide (CO) is mainly produced from the photoreduction, with an evolution rate of 142.1 µmol h^-1. Yet, in a polymer framework with O and N sites, CH₄ is the only carbon-based product from the photoreduction, with a production rate of 263.7 µmol h^-1. O and N sites of the polymer framework lead CO₂ to be converted into CO which bonds to photocatalyst strongly and prefer to undergoing hydrogenation to CH₄, thus changing carbon-based product from CO to CH₄. This opens a new way to achieve more efficient selective photoreduction of CO₂.