# Electrocatalysis by Coinage Metal Nanoclusters of Atomic Precision: Tailoring Catalytic Reactivity and Stability by Ligands and Composition

## TL;DR

This review explores how coinage metal nanoclusters can be tailored for efficient electrocatalysis, focusing on how ligands and composition affect performance.

## Contribution

The paper provides a comprehensive overview of how ligand types and nanocluster composition influence electrocatalytic performance, particularly for CO2 reduction.

## Key findings

- Alkynyl ligands enhance active-site exposure and catalytic performance in CO2 reduction.
- Cu-based nanoclusters enable the production of value-added multicarbon products from CO2.
- Surface chemistry and ligand engineering significantly impact electrocatalytic activity and selectivity.

## Abstract

Atomically precise coinage metal nanoclusters (NCs) have emerged as a powerful platform for uncovering structure–property relationships and for various applications. aOwing to their well‐defined atomic structures, discrete electronic states, and tunable surface environments, these NCs enable systematic studies of active‐site modulation at the atomic level, which is especially important for nanocatalysts and has long been pursued in heterogeneous catalysis. This review provides a comprehensive overview of recent advances in the electrocatalytic applications of coinage metal NCs protected by thiolate, phosphine, amine, and alkynyl ligands. In addition to the size dependence, key effects—ligand types, morphology, core doping, and surface modification—on the CO2 reduction reaction (CO2RR) are discussed first. Then, cases of non–alkynyl‐protected NCs with exceptional CO2RR activities are illustrated to show how atomic packing, ligand engineering, lattice hydride, and alloying can be used to design high‐performance NC catalysts. Cu‐based NCs are highlighted since value‐added multicarbon products can be created in CO2RR. The review then discusses how alkynyl protection introduces unique metal–ligand interfacial structures via σ–π anchoring, leading to reduced ligand coverage and increased exposure of active sites of metal. Recent progress in alkynyl‐protected NCs has expanded the accessible structural library, enabling efficient electrocatalysis for CO2RR, nitrate reduction (NO3
−RR), and hydrogen evolution reaction (HER). The synergistic effects of bimetallic compositions, ligand functionalization, and nanocluster architectures are examined in detail, illustrating how subtle changes in surface chemistry translate into dramatic improvements in catalytic performance. Through comparisons between non–alkynyl‐ and alkynyl‐protected NCs, this review underscores the central role of surface chemistry in tailoring electrocatalytic activity, selectivity, and stability. Finally, future directions are outlined, emphasizing the importance of combining atomic‐level structural precision with rational ligand engineering and heteroatom doping to design next‐generation electrocatalysts.

Atomically precise coinage metal nanoclusters offer an exceptional platform for probing structure–activity relationships in electrocatalysis. This review first outlines general catalyst‐design principles, emphasizing how ligand environment, morphology, doping, and surface modification govern electrocatalytic behavior. We then compare non‐alkynyl and alkynyl systems, highlighting how ligand anchoring and engineering enhance active‐site exposure. Special attention is given to Cu‐based nanoclusters, which uniquely enable value‐added C2 product formation, illustrating their potential for advanced CO2 conversion.
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