Conformal surface intensive doping of low-valence Bi on Cu2O for highly efficient electrochemical nitrate reduction to ammonia production

Electrochemical nitrate reduction reaction (NO3RR) 3 RR) has been regarded as a promising alternative to the Haber-Bosch process for sustainable and clean NH3 3 production. To develop highly active and stable electrocatalysts for NO3 3 - to NH3 3 production, Cu-based materials have been considered as potential candidates owing to the excellent NO3- 3 - adsorption to easily overcome the rate determining step of nitrate to nitrite conversion in NO3RR, 3 RR, although the poor NH3 3 yield rate is still challenging. In this study, we report a hybrid electrocatalyst with Bi dopant substitutionally incorporated on cuboctahedra Cu2O 2 O platform (Bi/Cu2O) 2 O) via in-situ hydrothermal method. The Bi/Cu2O 2 O shows the NH3 3 yield rate of 2562.56 lg h-1 mg cat-1 and Faradaic efficiency of 99.2 % at-0.8 V versus reversible hydrogen electrode in a neutral electrolyte, which is the highest performance among previously reported Cu-based electrocatalyst for NO3RR 3 RR to NH3. 3 . The interfacial synergetic effect of sufficient protonation from Bidoped overlayer and efficient NO3- 3 - adsorption from the Cu2O 2 O platform results in excellent NO3RR 3 RR performance. The experimental variable investigations with in-situ attenuated total reflectance-Fourier transform infrared measurement elucidate that not only nitrate to nitrite conversion but also the protonation of *NO2 2 is the rate limiting step for NH3 3 production.