Abstract
The electrochemical CO
2
reduction reaction (CO
2
RR) represents a sustainable approach to convert the continuously accumulating CO
2
emission into fuels or value-added chemicals. Tin and its compounds are recognized as formate selective CO
2
RR 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 SnO
2
nanoparticle-decorated hollow carbon spherical structure (SnO
2
/C) as an efficient CO
2
RR electrocatalyst. Compared to the plain SnO
x
nanoparticle-aggregated hollow spheres and hollow carbon spheres, SnO
2
/C achieved a much enhanced CO
2
RR catalytic performance, including better faradaic efficiencies (FE) and enhanced electrochemical stability. The much improved CO
2
RR activity and stability of SnO
2
/C were attributed to the Sn–O–C linkages between SnO
2
and the carbon sphere, which led to the increased CO
2
chemisorption, fast electron transfer, and the increased number of catalytically active sites.