Efficient electrocatalytic reduction of N2 to ammonia at ambient conditions with municipal sludge-derived porous carbon codoped with multiple heteroatoms

Electrocatalytic reduction of N 2 to ammonia (NH 3 ) at ambient conditions has attracted widespread attention, and revealing the mechanism has been a remarkably challenging problem for decades. This work developed a low-cost and efficient multiple heteroatom codoped porous carbon catalyst from municipal sludge (MSB-P), which demonstrated excellent electrochemical stability and selectivity for the electrochemical N 2 reduction reaction (N 2 RR). In 0.1 mol/L HCl solution, a high NH 3 yield rate of 35.76 µg. h   −   1 .mg −1 cat. and an excellent Faraday Efficiency (FE) of 7.79% at -0.7 V vs. RHE (reversible hydrogen electrode) were obtained under ambient conditions. Furthermore, the electrocatalytic mechanism of MSB-P for N 2 RR was also revealed by in situ Fourier transform infrared spectroscopy (FTIR) data, and an associative route was identified. These findings provide an exciting new method for fabricating inexpensive and efficient carbon-based catalysts for production of NH 3 at ambient conditions.