Tandem Nitrate-to-Ammonia Conversion on Atomically Precise Silver Nanocluster/MXene Electrocatalyst

Electrocatalytic reduction of nitrate (NO3RR) to synthesize ammonia (NH3) provides a competitive manner for carbon neutrality and decentralized NH3 synthesis. Atomically precise nanoclusters, as an advantageous platform for investigating the NO3RR mechanisms and actual active sites, remain largely underexplored due to the poor stability. Herein, we report a (NH4)9[Ag9(mba)9] nanoclusters (Ag9 NCs) loaded on Ti3C2 MXene (Ag9/MXene) for highly efficient NO3RR performance towards ambient NH3 synthesis with improved stability in neutral medium. The composite structure of MXene and Ag9 NCs enables a tandem catalysis process for nitrate reduction, significantly increasing the selectivity and FE of NH3. Besides, compared with individual Ag9 NCs, Ag9/MXene has better stability with the current density performed no decay after 108 hours of reaction. This work provides a strategy for improving the catalytic activity and stability of atomically precise metal NCs, expanding the mechanism research and application of metal NCs. Silver nanoclusters loaded on Ti3C2 MXene (Ag9/MXene) displays highly efficient NO3RR performance towards ambient NH3 synthesis in neutral medium. The composite structure of MXene and Ag9 NCs enables a tandem catalysis process for nitrate reduction, significantly increasing the selectivity and FE of NH3.image