Proceedings of MATSUS Spring 2024 Conference (MATSUS24)
DOI: https://doi.org/10.29363/nanoge.matsus.2024.552
Publication date: 18th December 2023
Herein we describe a novel type of hybrid material for the reduction of CO2 under high reaction rates. It consists of nanocrystalline organometallic clusters whose core comprises several covalently linked silver or copper atoms, with organic ‘ligands’ orderly distributed in the outer shell. Known as silver acetylides, these molecules involve stable alkyne-metal covalent bonds, allowing for the direct modulation of the metal clusters’ electronic properties by tailoring the chemical structure of the organic moiety. The versatility of these catalysts is further enhanced by the fact that their synthesis involves only one highly selective synthetic step from an alkyne precursor and a silver salt and can be carried out on a multigram scale without any purification step. The metal acetylides form readily from mixing aqueous and methanolic solutions of the latter precursors as highly insoluble species. Therefore, large libraries of catalysts can be synthesised from a vast selection of commercially available alkyne precursors. The catalytic properties of such entities were discovered only very recently, with only three alkynyl clusters (silver and gold) reported for the reduction of CO2 in laboratory-scale electrolysis systems. We took the field a significant leap further from reported literature studies, demonstrating the ability of alkynyl silver clusters to efficiently catalyse the CO2 reduction reaction under high reaction rates in a flow cell electrolyser. Electrolysis currents well above 200 mA/cm2, a widely accepted benchmark, were achieved with high selectivity towards CO (>95% FE) a remarkable stability