Gold Nanoclusters as Electrocatalysts: Atomic Level Understanding from Fundamentals to Applications

Abstract

Recently, gold nanoclusters (Au NCs) have become more popular as their structure–property relationships start to rival those of conventional Au NPs. The molecular-type energy transition and quantum confinement effects of Au NCs are fundamentally different from those of Au NPs. Because of these intriguing features, Au NCs are gaining special attention in catalysis research and are being used as model catalysts to understand catalytic properties and structures at the atomic level. Although catalysis research is a longstanding discipline, the fundamental insights into structure–property relationships at the atomic level, such as reaction mechanism/activation at the catalyst surface and identification of actives sites, remain largely unexplored. Atomically precise Au NCs can provide access to such information because of their exact molecular information, monodisperse nature, molecule-like properties, and well-resolved atomic structure from X-ray crystallography, akin to protein structures in enzyme-based catalysis. This accurate data also provides essential information for computational investigations. In this Perspective, we summarize the recent progress made using Au NCs as electrocatalytic materials for oxygen reduction, water electrocatalysis, and electrochemical reduction of carbon dioxide, and we discuss challenges to overcome existing limitations. We hope that our Perspective motivates more researchers to investigate different aspects of Au NCs toward a better understanding of the structure–performance correlations in catalysis.

Surface environment complication makes Ag29 nanoclusters more robust and leads to their unique packing in the supracrystal lattice

“…14–20 Consequently, metal nanoclusters are an emerging class of programmable nanomaterials for several promising applications, such as catalysis, drug delivery, energy storage, and biological applications. 21–24…”

The Factors Dictating Properties of Atomically Precise Metal Nanocluster Electrocatalysts

“…To the best of our knowledge, the most important goal in electrocatalysis (also other heterocatalysis) is to correlate the atomic-level structure of NPs with their catalytic properties and delineates the factors that dictate their catalytic properties. [26,27,33,35,52,158] Recent years have witnessed great progress in syntheses of the atomically precise metal NCs and the successful determination of their structures by X-ray crystallography, which constitutes an important step in dictating their structure-property correlations. In this review, we summarize the advances in the utilization of atomically precise metal nanoclusters for electrocatalysis.…”

“…[7,[15][16][17] Mass-selection and soft-landing have widely been applied in the preparation of size-selected metal clusters, and the catalytic electrochemical catalysis applications of NCs. [27,[51][52][53] Nevertheless those reports rarely systematically discuss the factors regulating the catalytic performance of the NCs catalysts. Therefore, in this review, the factors, such as size, metal doping/alloying, ligand engineering, charge state of clusters as well as support materials, affecting electrochemical catalytic performance of NCs catalysts, are summarized and highlighted.…”

“…[19][20][21][22][23][24][25] More importantly, progress in the structural determination of NCs by X-ray crystallography provides an opportunity to better understand their structural evolution and structure-property relationship. [1,2,[26][27][28][29][30][31][32] Typically, the NCs consist of a precise number of metal atoms (n) and ligands (m) with n ranging up to a few hundred atoms (denoted as Au n L m ), and can be regarded as a new class of catalytic materials holding promise in fundamental catalysis research. [33][34][35][36][37][38][39] When the sizes of the particle are decreased to the sub-nanometre regime, both the geometric and electronic structures of the particle are distinct from plasmonic metal nanoparticles (see Figure 1).…”

“…[44][45][46][47][48][49][50] The first review based on metal NCs catalysis was contributed by Jin and co-workers in 2013 and several relative reviews were released from different groups thereafter. [1,27,[51][52][53] Nevertheless electrochemical catalysis does not occupy a very important portion in those reviews, and typically, there is a tendency to expound NCs catalysis based on different electrochemical catalytic systems such as hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR), carbon dioxide reduction (CO 2 RR) and other electrochemical catalytic oxidation reactions, when discussing the Metal nanoparticles occupy an important position in electrocatalysis. Unfortunately, by using conventional synthetic methodology, it is a great challenge to realize the monodisperse composition/structure of metal nanoparticles at the atomic level, and to establish correlations between the catalytic properties and the structure of individual catalyst particles.…”