Anchoring and activation of catalytic sites on the clusters via intermolecular interactions

Abstract

Constructing catalytically active sites on the clusters is a mainstream strategy to optimize their catalytic properties. However, it generally leads to unpredictable variations due to the notoriously sensitive relationship between the adduct group and the structure of metal nanoclusters. In this study, a strategy within Au–Cd bimetallic clusters was proposed to achieve controllable modification of the cluster surface through Lewis acid-base specific binding between the recognition group and the cluster, thereby forming Au-Cd-pyridine units. Taking the ORR as a model reaction, the results show that the formed Au-Cd-pyridine catalytic sites can significantly enhance the catalytic activity. Further, we explored the catalytic mechanism using ESI-MS, XPS, and SC-XRD, as well as DFT calculations, and revealed that the ternary catalytic centers regulate the adsorption behavior of OOH* intermediates (enhancement and change of adsorption mode from bridge-form to top-form). The pyridine-modified Au27Cd2 catalyst also demonstrates performance enhancement when extending its application to other electrocatalytic reactions, i.e. NO3RR and HER. Finally, the Au16Cd3 cluster, which contained the Au-Cd-pyridine motifs, was prepared to confirm further the key role of Au-Cd-pyridine binding in enhancing catalytic activity