Abstract
<jats:p> Direct Air Capture (DAC) of CO <jats:sub>2</jats:sub> and its conversion into value-added products are critical for a sustainable economy. Current methods require to sequentially concentrate then convert the CO <jats:sub>2</jats:sub> , and catalytic systems are often highly affected by the presence of O <jats:sub>2</jats:sub> from air, thereby preventing a direct reduction of CO <jats:sub>2</jats:sub> in air. This works presents a copper(I) hydride catalyst [(dppbz)CuH] (1), that efficiently reduces highly diluted CO <jats:sub>2</jats:sub> (down to 0.5 % in inert gas) into silyl formate, using hydrosilanes as mild reductants. Remarkably, the system retains high activity (up to 92% yield) even in the presence of 20% O <jats:sub>2</jats:sub> , and remains active after multiple cycles. Mechanistic studies (DFT and NMR) reveal that using a mixed alkyl-alkoxy substituted hydrosilane is key to stabilize hypervalent silicon intermediates, lowering the overall energetic demand. The dimeric formate complex [(Cu(μ-OCHO)(dppbz)) <jats:sub>2</jats:sub> ] (5) was isolated, and demonstrated to be the resting state of the reaction, while the rate-determining step correspond to the transmetallation of the formate moiety to the hydrosilane. </jats:p>