Control of exposed crystal planes of CeO2 enhances electrocatalytic nitrate reduction

Cerium dioxide (CeO2) has emerged as a promising electrocatalyst for electrocatalytic nitrate reduction to produce ammonia (NRA). However, the NRA performance of CeO2 still needs to be improved and the interface-related NRA electrocatalytic activity of CeO2 is unclear. Herein, CeO2 with exposed (111) or (200)/(220) planes is prepared by adjusting the amount of added surfactant simply. The CeO2 with exposed (220)/(200) planes presents higher NRA performance than that of CeO2 with the exposed (111) plane. Based on density functional theory, the enhanced mechanism is revealed. The exposed (111) plane of CeO2 repels $$\mathrm{NO}_{3}^{-}$$ , interrupting the following NRA processes. For exposed (200)/(220) planes of CeO2, they show high affinity for $$\mathrm{NO}_{3}^{-}$$ and relatively low energy barriers for NRA reactions, bringing about enhanced NRA performance. This work shows a crystal-plane-dependent strategy for enhancing the catalytic performance of electrocatalysts.