Abstract
CO(2) reduction catalyst corrosion and H(2) evolution remain challenging under the strongly acidic electrolyte. Here, Ga-modulated SnO(x) was investigated to achieve a good Sn(δ+) oxidation state stability for durable (> 4000 hours) acidic CO(2) reduction to HCOOH. Under pH 1.7, catalysts achieved a partial current density of 440 mA cm(-2) at -1.63 V(RHE) and the highest single-pass conversion efficiency (SPCE) of 91.9%. In a 10 cm(2) electrolyzer, a total current of ~986.3 milliampere is exhibited for more than 4000 hours with Faradaic efficiency of HCOOH (FE(HCOOH)) higher than 82% and SPCE higher than 50%. Mechanism study indicates that lattice oxygen anchoring effect of Ga due to its strong oxygen affinity establishes a stable framework, reinforcing interface Sn─O bonds and protecting the Sn(δ+) from the heavy self-reduction process. The robust structure of catalyst and modulated active Sn(δ+) sites elevate the CO(2) reduction activity. The durable and highly efficient catalytic system exhibits the potential for industrial applications of the Ga-modulated SnO(x).