Coordination Engineering of Pd nanoclusters for highly efficient electrocatalytic conversion of nitrate to ammonia

• Published in: Chemical engineering science Vol. 312; p. 121662
• Main Authors: Yang, Chen, Jia, Yunjiao, Xiao, Hang, Chong, Ben, Ou, Honghui, Zhang, Bin, Yang, Guidong
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.06.2025
• Subjects: Ammonia synthesis; Coordination environment; Electrocatalysis; Nanoclusters; Nitrate reduction; Electrocatalysis; Coordination environment; Ammonia synthesis; Nitrate reduction; Nanoclusters
• ISSN: 0009-2509
• DOI: 10.1016/j.ces.2025.121662

We designed palladium nanoclusters with different coordination environments (C, N, O, and P), embedded palladium with different precursors in different coordination structures, and attached palladium to carbon nanotube substrates. Different non-metallic elements (C, N, O, and P) can effectively regulate the adsorption and desorption of intermediates (*NO, *NHO, *NH3) at the active site to avoid extreme cases of adsorption and desorption, thereby increasing ammonia production. [Display omitted] •A novel molecular-restricted method for synthesizing Pd nanoclusters with diverse coordination.•The phosphorus (P) coordinated Pd-P NCs exhibits outstanding catalytic activity and selectivity for the NO3-RR.•Density Functional Theory (DFT) provides the reaction mechanism, emphasizing the influence of the environments.•The study offers a pragmatic approach for optimizing the modulation of coordination environments. How to achieve high energy efficiency ammonia (NH3) synthesis is an important subject in energy industry. The traditional Haber-Bosch process demands high energy consumption and high CO2 emissions, so electrochemical reduction of nitrate selectivity for NH3 under ambient conditions offers a promising solution. In this study, the average size of palladium nanoclusters was ∼ 0.5 nm, and in order to obtain high NH3 activity and selectivity simultaneously, palladium nanoclusters with different ligands were designed. The experiments demonstrated that the Pd-P coordination endows the supported Pd nanoclusters highest ammonia Faraday efficiency of 92.8 % and ammonia yield 1329.4 mmol h−1 gcat-1. To decipher the ligand coordination effect on the catalytic performance, advanced techniques and theoretical analyses were applied for clarifying the reaction pathways and illustrating the role of electronegative P in facilitating NH3 production.