Visible-Light-Driven Methanol-To-Ethanol Conversion via Carbene Pathway by Frustrated Lewis Pairs.

Carbenes are critical intermediates in organic chemistry, recognized for their exceptional reactivity and versatility. However, conventional methods for carbene generation are often associated with safety risks and hazardous procedures. This study presents a Ga-ZnO1-x nanosheets photocatalyst with a (100) preferred orientation, featuring abundant refined frustrated Lewis pair (FLP) sites, excellent light absorption, and efficient charge transport properties. Under visible light irradiation, this catalyst activates methanol to generate a methyl carbene (methylene) intermediate, which subsequently reacts with another methanol molecule to produce ethanol. In situ experiments and theoretical calculations reveal that FLP sites, composed of oxygen vacancies and Ga, respectively activate C-H and C-O bonds while efficiently capturing photogenerated electrons and holes, making the most significant contribution to the formation of carbene intermediates. This research not only offers an eco-friendly route for methanol-to-ethanol conversion but also establishes a safer and more efficient method for methyl carbene production under mild conditions.