Modulating intermediate coverage on atomically dispersed Co modified Cu2O for efficient nitrate reduction across a wide temperature range

The practical implementation of electrocatalytic nitrate reduction reaction (NO 3 RR) for ammonia synthesis is critically hindered by its inherent sensitivity to temperature fluctuations, which leads to unpredictable selectivity shifts among NO 3 RR, nitrite reduction reaction (NO 2 RR), and the hydrogen evolution reaction (HER). Using Cu 2 O as a model catalyst, the temperature-dependent competition among different pathways within the 10–40 °C range was elucidated. An atomically dispersed Co-doped Cu 2 O catalyst (Co-Cu 2 O) was then designed to function as a thermal-adaptive platform. Mechanistic studies reveal that the atomically dispersed Co sites not only enhance the intrinsic hydrogenation capability but also dynamically stabilize key N-H intermediates (*NOH, *NH 2 , and *NH 3 ) against temperature variations. This synergistic effect stabilizes the reaction pathway toward NH 3 , enabling robust and selective ammonia production under thermal perturbations. As a result, the Co-Cu 2 O catalyst maintains a Faradaic efficiency (FE) for NH 3 above 90 % across the entire 10–40 °C temperature window and achieves a remarkable NH 3 production rate of 53.79 mg h −1 mg cat −1 at 40 °C. This work provides fundamental insights into temperature-mediated catalysis and establishes an effective design strategy for wide-temperature electrocatalysts.