Applications of metal nanoclusters supported by two-dimensional material graphene in electrocatalytic carbon dioxide reduction

Abstract

Metal nanoclusters (MNCs) have been demonstrated to exhibit superior catalytic performance compared to single nanoparticles. This is attributed to their quantized electronic structure, unique geometrical stacking and abundant active sites. While these exposed metal atoms can markedly enhance the efficiency of catalysis, unfortunately, MNCs are susceptible to agglomeration, which impairs their catalytic activity and stability. Graphene is a single atomic layer of two-dimensional material formed by the hybridization of the s and p orbitals of carbon atoms. It exhibits stable physical and chemical properties and an easily controllable structure, rendering it an ideal carrier for MNCs. When metal nanoclusters (MNCs) are loaded on a graphene substrate, the MNCs can form a stable binding site with the graphene substrate. Furthermore, the construction of a defective structure on the graphene substrate enables the formation of robust interactions between the metal atoms of the MNCs and the substrate, facilitating the rapid establishment of electron conduction pathways and markedly enhancing the electrocatalytic performance. This paper presents a review of the applications of metal nanoclusters supported on graphene skeletons in the field of electrocatalytic CO₂ reduction (CO₂RR). Firstly, we briefly introduce the reaction mechanism of CO2RR, then, we systematically discuss the synthesis strategies, properties and progress of metal nanoclusters in electrocatalytic carbon dioxide reduction from both experimental and theoretical perspectives, and lastly, we put forward the opportunities and challenges for metal nanocluster catalysts supported on carbon materials.