Molecular Engineering at Electrode Interface Enables Efficient Catalytic Nitrogen Reduction
De‐Shan Zhang, Jian Li, Lei Zhu, Ke Zhang, Yi‐Xuan Wang, Jing‐Hao Wang, Chen Zhang, Chen Ye, Zhi‐Jun Li, Yu‐Zhe Chen, Chen‐Ho Tung, Li‐Zhu WuABSTRACT
Molecular catalysts are promising for nitrogen (N 2 ) fixation due to their well‐defined sites and tunable coordination, yet most molecules in homogeneous systems reside in the bulk solution, leading to poor catalyst utilization. Here, we introduced a molecular engineering strategy by assembling a functionalized molecular molybdenum complex (PyMoBr 3 PNP) on graphdiyne (GDY) through π–π interactions. The resulting interface‐assembled molecular electrode, PyMoBr 3 PNP/GDY/carbon paper (CP), catalyzed N 2 conversion to ammonia (NH 3 ) using 2,4,6‐trimethylpyridinium triflate ([ColH][OTf]) as the proton source. Rigorous isotopic labeling and continuous time‐dependent controls confirmed the genuine nature of catalytic N 2 to NH 3 turnover. Encouraged by the intrinsic N 2 reduction activity, the PyMoBr 3 PNP/GDY/CP cathode was further coupled with a molecular hybrid photoanode (ZnTCPP/Al 2 O 3 /BiVO 4 ) for photoelectrocatalytic N 2 reduction. The integrated system decreased the applied bias, achieved a turnover frequency (TOF) of 47.52 h −1 and a turnover number (TON) of 157.54 over 4 h for NH 3 production, representing the highest performance reported to date for molecular‐based electrochemical and photoelectrochemical N 2 reduction. All of these results highlight the potential of molecular engineering platforms to enhance catalyst utilization, improve reaction efficiency, and lower energy consumption for N 2 fixation.