Preventing Nitrite Desorption via Switching Hydrogenation Position: A Dual‐Site Approach for Selective Nitrate Reduction to Ammonia

Abstract The electrochemical nitrate reduction reaction (NO 3 RR), which converts harmful nitrates into valuable ammonia (NH 3 ) with zero carbon emission, is one of the most promising alternatives to the Haber–Bosch process. However, the NO 3 RR process is complex and involves multiple proton‐coupled electron transfers that generate intermediates or byproducts, such as NO 2 − , resulting in low ammonia yields and faradaic efficiency (FE). Herein, by constructing a FeCu bimetallic catalyst (FeCu‐NC), the hydrogenation position of *NO 3 is switched at the FeCu dual‐atom site, preventing the desorption of *NO 2 intermediate. Furthermore, electron transfer from Cu to Fe sites mimics the electron flow direction in natural nitrite reductase enzymes and accelerates the reduction of *NO 2 to NH 3 , achieving efficient conversion of NO 3 − to NH 3 . A 24‐hour electrocatalytic experiment with FeCu‐NC demonstrates negligible NO 2 − formation throughout the NO 3 RR process, with an ammonia production rate of 6.13 mg h −1 mg cat −1 and an impressive FE of 95%, which are remarkably superior in comparison to most of the NO 3 RR electrocatalysts. This work opens new avenues for the fundamental understanding of catalytic mechanisms and the development of next‐generation catalysts for sustainable ammonia production.