Sub-5 nm SnO2 chemically coupled hollow carbon spheres for efficient electrocatalytic CO2 reduction

Abstract

The electrochemical CO₂ reduction reaction (CO₂RR) represents a sustainable approach to convert the continuously accumulating CO₂ emission into fuels or value-added chemicals. Tin and its compounds are recognized as formate selective CO₂RR catalysts, while their catalytic activities and stabilities significantly depend on the micro/nanostructures and the corresponding electronic structures of the catalysts. Herein, we developed a sub-5 nm SnO₂ nanoparticle-decorated hollow carbon spherical structure (SnO₂/C) as an efficient CO₂RR electrocatalyst. Compared to the plain SnO_x nanoparticle-aggregated hollow spheres and hollow carbon spheres, SnO₂/C achieved a much enhanced CO₂RR catalytic performance, including better faradaic efficiencies (FE) and enhanced electrochemical stability. The much improved CO₂RR activity and stability of SnO₂/C were attributed to the Sn–O–C linkages between SnO₂ and the carbon sphere, which led to the increased CO₂ chemisorption, fast electron transfer, and the increased number of catalytically active sites.