Nitrogen reduction reaction (NRR) under ambient conditions is always a long-standing challenge in science,due to the extreme difficulty in breaking the strong N=N triple bond.The key to resolving this issue undoubtedly lies in searching superior catalysts to efficiently activate and hydrogenate the stable nitrogen molecules.We herein evaluate the feasibility of WP2 for N2 activation and reduction,and first demonstrate WP2 with an impressive ammonia yield rate of 7.13 μg h-1 cm-2,representing a promising W-based catalyst for NRR.DFT analysis further reveals that the NRR catalysis on WP2 proceeds in a distal reaction pathway,and the exceptional NRR activity is originated from superior surface electron energy level matching between WP2 and NRR potential which facilitates the interfacial proton-coupled electron transfer dynamics.The successfully unraveling the intrinsic catalytic mechanism of WP2 for NRR could offer a powerful platform to manipulate the NRR activity by tuning the electron energy levels.