Efficient nitric oxide reduction to ammonia on a metal-free electrocatalyst

NH3 synthesis and NO removal are two of the most attractive and challenging processes in electrochemistry. Current research efforts mainly focus on them separately, while the direct electrochemical reduction of NO to NH3 has been less explored. Herein, based on first-principles calculations, we propose a metal-free electrocatalyst, namely, P atom doped single-layer C2N, as a promising candidate system for achieving the direct electroreduction of NO to NH3. Particularly, double P doped C2N (2P@C2N) exhibits excellent catalytic activity and high selectivity, which correlates with the sp(3) hybridization of the P atom. Moreover, our microkinetic modeling analysis shows that the turnover frequency of NO reduction to NH3 on 2P@C2N is as large as 8.9 x 10(5) per s per site at 400 K, suggesting that it exhibits an ultra-fast reaction rate. Our study provides not only the first metal-free electrocatalyst for NO removal, but also an effective alternative avenue for ammonia synthesis.