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

[Display omitted] Electrochemical nitrate reduction reaction (NO 3 RR) has been regarded as a promising alternative to the Haber-Bosch process for sustainable and clean NH 3 production. To develop highly active and stable electrocatalysts for NO 3 – to NH 3 production, Cu-based materials have been considered as potential candidates owing to the excellent NO 3 – adsorption to easily overcome the rate determining step of nitrate to nitrite conversion in NO 3 RR, although the poor NH 3 yield rate is still challenging. In this study, we report a hybrid electrocatalyst with Bi dopant substitutionally incorporated on cuboctahedra Cu 2 O platform (Bi/Cu 2 O) via in-situ hydrothermal method. The Bi/Cu 2 O shows the NH 3 yield rate of 2562.56 μg 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 NO 3 RR to NH 3. The interfacial synergetic effect of sufficient protonation from Bi-doped overlayer and efficient NO 3 – adsorption from the Cu 2 O platform results in excellent NO 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 *NO 2 is the rate limiting step for NH 3 production. [ABSTRACT FROM AUTHOR]