1D SnO₂ with Wire‐in‐Tube Architectures for Highly Selective Electrochemical Reduction of CO₂ to C₁ Products

Electrochemical reduction of CO 2 (ERC) into useful products, such as formic acid and carbon monoxide, is a fascinating approach for CO 2 fixation as well as energy storage. Sn‐based materials are attractive catalysts for highly selective ERC into C 1 products (including HCOOH and CO), but still suffer from high overpotential, low current density, and poor stability. Here, One‐dimensional (1D) SnO 2 with wire‐in‐tube (WIT) structure is synthesized and shows superior selectivity for C 1 products. Using the WIT SnO 2 as the ERC catalyst, very high Faradaic efficiency of C 1 products (>90%) can be achieved at a wide potential range from −0.89 to −1.29 V versus RHE, thus substantially suppressing the hydrogen evolution reaction. The electrocatalyst also exhibits excellent long‐term stability. The improved catalytic activity of the WIT SnO 2 over the commercial SnO 2 nanoparticle indicates that higher surface area and large number of grain boundaries can effectively enhance the ERC activity. Synthesized via a facile and low‐cost electrospinning technology, the reduced WIT SnO 2 can serve as a promising electrocatalyst for efficient CO 2 to C 1 products conversion.