Photochemical H <sub>2</sub> dissociation for nearly quantitative CO <sub>2</sub> reduction to ethylene
Ping Jin, Pu Guo, Nengchao Luo, Hui Zhang, Chenwei Ni, Ruotian Chen, Wei Liu, Rengui Li, Jianping Xiao, Guoxiong Wang, Fuxiang Zhang, Paolo Fornasiero, Feng Wang
Abstract
Producing olefins by carbon dioxide (CO 2 ) hydrogenation is a long-standing goal. The usual products are multicarbon mixtures because the critical step of heterolytic hydrogen (H 2 ) dissociation at high temperatures complicates selectivity control. In this study, we report that irradiating gold–titanium dioxide at 365 nanometers induces heterolytic H 2 dissociation at ambient temperature. This process likely relies on interfacial electric dipoles from photogenerated electrons and holes situated on the metallic gold nanoparticles and interfacial gold–oxygen–titanium scaffolds. The heterolytic H 2 dissociation is further promoted by light-induced coating of gold nanoparticles with a titanium oxide layer. The resulting nucleophilic hydrogen species reduce CO 2 to ethane in >99% yield under light irradiation in a flow apparatus. Furthermore, cascading with a subsequent photocatalytic ethane dehydrogenation generates ethylene in >99% yield over 1500 hours of irradiation.