Electrochemical reduction of carbon dioxide (CO2 ) into chemicals and fuels has recently attracted much interest, but normally suffers from a high overpotential and low selectivity. In this work, single P atoms were introduced into a N-doped carbon supported single Fe atom catalyst (Fe-SAC/NPC) mainly in the form of P-C bonds for CO2 electroreduction to CO in an aqueous solution. This catalyst exhibited a CO Faradaic efficiency of ≈97 % at a low overpotential of 320 mV, and a Tafel slope of only 59 mV dec-1 , comparable to state-of-the-art gold catalysts. Experimental analysis combined with DFT calculations suggested that single P atom in high coordination shells (n≥3), in particular the third coordination shell of Fe center enhanced the electronic localization of Fe, which improved the stabilization of the key *COOH intermediate on Fe, leading to superior CO2 electrochemical reduction performance at low overpotentials.
Keywords: CO2 electroreduction; electron localization; low overpotentials; phosphorous; single Fe atom.
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