Abstract
The nitrate (NO(3)(-)) electroreduction into ammonia (NH(3)) represents a promising approach for sustainable NH(3) synthesis. However, the variation of adsorption configurations renders great difficulties in the simultaneous optimization of binding energy for the intermediates. Though the extensively reported Cu-based electrocatalysts benefit NO(3)(-) adsorption, one of the key issues lies in the accumulation of nitrite (NO(2)(-)) due to its weak adsorption, resulting in the rapid deactivation of catalysts and sluggish kinetics of subsequent hydrogenation steps. Here we report a tandem electrocatalyst by combining Cu single atoms catalysts with adjacent Co(3)O(4) nanosheets to boost the electroreduction of NO(3)(-) to NH(3). The obtained tandem catalyst exhibits a yield rate for NH(3) of 114.0 mg NH3 h(-1) cm(-2), which exceeds the previous values for the reported Cu-based catalysts. Mechanism investigations unveil that the combination of Co(3)O(4) regulates the adsorption configuration of NO(2)(-) and strengthens the binding with NO(2)(-), thus accelerating the electroreduction of NO(3)(-) to NH(3).