Electrocatalytic CO Reduction to Produce Long-chain Products Through Fischer-Tropsch Pathway

Abstract

Electrocatalytic CO reduction (COR) is a promising approach for converting C₁ feedstock into valuable multi-carbon fuels using renewable electricity. At ambient temperature, COR, particularly on Cu-based catalysts, typically produces C₂ chemicals as the dominant products, with long-chain hydrocarbons containing more than five carbon atoms rarely forming. In contrast, Fischer-Tropsch synthesis (FTS), a thermocatalytic process converting CO and H₂, selectively generates long-chain hydrocarbons. In this study, we utilized Ru nanoparticles for electrochemical COR under elevated conditions (423 K and 2.8 MPa). Long-chain products with up to 21 carbon atoms were detected, achieving a Faradaic efficiency of 32 % and a weight selectivity of 65 % for C₅₊ products. We propose an FTS-like pathway for this electrocatalytic process. Unlike thermocatalytic FTS, where adsorbed H atoms form via H₂ dissociation, in this electrocatalytic version, the H atoms are generated through the Volmer reaction from water. Subsequently, the chemisorbed and activated CO species are hydrogenated, forming CH_x intermediates that propagate into long-chain products.