Single atoms have been widely applied as efficient catalysts in various catalytic systems due to its high selectivity for certain products, which is induced by a uniform coordinate environment of active sites. Herein, it is demonstrated that Bi single atoms anchored on carbon black (Bi SAs/C) can serve as an efficient catalyst for CO2 electroreduction into formate (HCOO- ). During CO2 electroreduction, Bi SAs/C achieved a faradaic efficiency for HCOO- of 83.6 % at-1.1 Vversus reversible hydrogen electrode (V vs. RHE). Notably, the selectivity for HCOO- of Bi SAs/C was always higher than 95 % at all applied potentials. In addition, at-1.2 Vvs.RHE, the current density for HCOO- formation in thepresence of Bi SAs/C reached-12.0 mA cm-2 , which was 3.4 times as high as that (-3.5 mA cm-2 ) of BiOx clusters on carbon black (BiOx /C). Mechanistic studies revealed that Bi SAs/C facilitated the faradaic process and accelerated reaction kinetics in comparison with BiOx /C.
Keywords: CO2; bismuth; electroreduction; formate formation; single-atom catalysts.
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