Amorphous Boron Carbide on Titanium Dioxide Nanobelt Arrays for High‐Efficiency Electrocatalytic NO Reduction to NH3

Electrocatalytic NO reduction is regarded as an attractive strategy to degrade the NO contaminant into useful NH3, but the lack of efficient and stable electrocatalysts to facilitate such multiple proton‐coupled electron‐transfer processes impedes its applications. Here, we report on developing amorphous B2.6C supported on a TiO2 nanoarray on a Ti plate (a‐B2.6C@TiO2/Ti) as an NH3‐producing nanocatalyst with appreciable activity and durability toward the NO electroreduction. It shows a yield of 3678.6 μg h−1 cm−2 and a FE of 87.6 %, superior to TiO2/Ti (563.5 μg h−1 cm−2, 42.6 %) and a‐B2.6C/Ti (2499.2 μg h−1 cm−2, 85.6 %). An a‐B2.6C@TiO2/Ti‐based Zn−NO battery achieves a power density of 1.7 mW cm−2 with an NH3 yield of 1125 μg h−1 cm−2. An in‐depth understanding of catalytic mechanisms is gained by theoretical calculations.