The synergistic tandem effect of Cu2+1O and Co3O4 enhances the activity and selectivity of nitrate reduction to ammonia in neutral solution

Construction the electrocatalysts with multiple components is an effective strategy to enhance the activity for NH 3 generation in electrocatalytic nitrate reduction reaction (NITRR). Herein, we report a high performance electrocatalyst Co 3 O 4 -Cu 2+1 O/CF. The obtained Co 3 O 4 -Cu 2+1 O/CF nanosheets not only provide large active surface area but also construct the bimetal oxides interface for exerting Cu-Co tandem catalysis. Meanwhile, Co 3 O 4 -Cu 2+1 O/CF exhibits a maximum NH 3 -Faradaic efficiency of 96.5% and NH 3 yield of 0.26 mmol h −1 cm −2 in neutral solution with 10 mM NO 3 - . The control experiments and Tafel analysis clearly manifest the tandem catalysis mechanism on Co 3 O 4 -Cu 2+1 O/CF, where Cu 2+1 O favors the NO 3 - conversion to NO 2 - , while Co 3 O 4 selectively promotes NO 2 - conversion to NH 3 . The DFT calculations reveal that the strengthened NO 3 - adsorption and the enhanced adsorption of H* on Co 3 O 4 -Cu 2+1 O/CF jointly promote the selective formation of ammonia from NO 3 - reduction. This work provides the strategy of constructing the efficient transition metal composited electrocatalysts in NITRR.