In situ Generation of Fluoride Catalysts for CO 2 ‐to‐Formic Acid Conversion With Silicon Reducing Agent

ABSTRACT The activation and catalytic reduction of carbon dioxide (CO 2 ) using silicon‐based reducing agents is an important strategy for sustainable C1 chemistry and silicon waste upcycling. Tetraalkylammonium fluoride salts are highly effective promoters of silicon hydride formation; however, their direct use introduces challenges in terms of expense and handling. Here, we report the first example of in situ generation of fluoride catalysts for the reduction of CO 2 to formic acid from a simple inorganic fluoride salt, such as NaF. A neutral precursor releases fluoride under mild conditions, enabling selective CO 2 reduction using powdered silicon. Mechanistic studies reveal that the catalytically active fluoride species are generated in situ from three components: inorganic fluoride, amine, and acid. The method eliminates the need for expensive and unstable organic fluoride. This work establishes a new fluoride‐mediated catalytic platform for coupling CO 2 valorization with silicon waste utilization.