Enabling Unconventional "Alternating-Distal" N₂ Reduction Pathway for Efficient Ammonia Electrosynthesis

The general understanding on the reaction path is that the electrocatalytic N₂ reduction follows either individual associative alternating or distal pathways, where efficient N₂ activation and selective NH₃ production are very challenging. Herein, an unconventional "alternating-distal" pathway was achieved by shifting the "*NHNH₂→*NH₂NH₂" to "*NHNH₂→*NH + NH₃" step to boost NH₃ synthesis with an amorphous CeMnO_x electrocatalyst. In this unconventional process, N₂ activation was realized through π back donation on the Mn site, while the Mn/Ce dual active sites could regulate the intermediate configurations to avoid the nitrogen-containing by-product formation. Such "alternating-distal" pathway was affirmed by in situ spectroscopic analyses and theoretical calculations. In a neutral media, an average ammonia production rate of 82.8 µg h^-1 mg^-1 and an outstanding Faradaic efficiency of 37.3% were attained. This work validated an unconventional mechanism in electrocatalytic ammonia synthesis, which might be extended to other catalytic process with multiple possible reaction paths.