Supported Sub‐Nanometer Clusters for Electrocatalysis Applications

Abstract

Single-atom catalysts (SACs) have attracted great attention in the field of electrocatalysis due to their exceptional activity, selectivity, 100% atom utilization, and tailorability of active sites at atomic level. The metal-support interactions and interatomic synergies, however, are severely limited due to the isolation of active sites in SACs which hinder their applications in some complex reactions. To this end, supported sub-nanometer cluster catalysts (SNCCs, <2 nm) with nearly fully exposed active atoms may outperform the SACs in some specific catalytic reactions. The presence of abundant chemical bonds in the clusters can flexibly regulate the support-cluster interaction and build ensemble effect in the sub-nanometer clusters for different electrocatalysis applications. In this review, recent advances of supported SNCCs in electrocatalysis applications are summarized and discussed for the first time. In particular, the importance of the support-cluster interactions and ensemble effect of the clusters in determining the catalytic performance of SNCCs are highlighted. Lastly, challenges and opportunities in SNCCs electrocatalysis are prospected.

Tailoring Interfacial Charge Transfer of Epitaxially Grown Ir Clusters for Boosting Hydrogen Oxidation Reaction

“…[12][13][14][15][16] Recent studies have demonstrated that supported sub-nanometer cluster catalysts (SNCCs) (<2 nm) can exhibit enhanced catalytic performance due to their unique geometric and electronic structure as well as synergistic effect among the atoms within the clusters. [17][18][19][20] The supported SNCCs also exhibit high atom utilization efficiency and can expose much more active atoms than corresponding nanoparticles in catalytic reactions. Meanwhile, compared with singleatom catalysts with uniformly isolated catalytic sites, the supported SNCCs can provide abundant active sites for the adsorption and activation of different intermediates.…”

Advances in the Electrocatalytic Hydrogen Evolution Reaction by Metal Nanoclusters‐based Materials

“…[48][49][50][51] Note that there are rare reviews on the MNCs and MNCs with different supports for HER, despite there being numerous reports about the MNCs as HER catalysts and some summaries for the nano-metric electrocatalysts recently. [52][53][54] This review, therefore, showcased recent advances in the activity-enhancing strategies of MNCs electrocatalysts, as well as the coordination and support-anchoring strategies. The organic-based structure, metal-based materials, and carbon matrix are systematically discussed as good and usually-used supports.…”

Microwave Synthesis of Pt Clusters on Black TiO2 with Abundant Oxygen Vacancies for Efficient Acidic Electrocatalytic Hydrogen Evolution

“…Improving the utilization efficiency, through the design of single atoms, [12–19] clusters, [20, 21] and specific morphologies [22–24] of Pt‐based catalysts, is a valid approach for reducing the cost of the developed electrocatalysts. Compared with nanoparticles and single atoms, [25–28] sub‐nanometer clusters could expose enough sites and enhance the specific performance simultaneously [29–32] . For instance, Baek and co‐authors [33] found that the Sn nanoclusters in nitrogen‐doped carbon polyhedra (Sn x NC) surpassed the electrocatalytic performance of Sn single atom catalyst for acidic oxygen reduction reaction, owing to the favorable oxygen species adsorption.…”

“…Compared with nanoparticles and single atoms, [25][26][27][28] sub-nanometer clusters could expose enough sites and enhance the specific performance simultaneously. [29][30][31][32] For instance, Baek and co-authors [33] found that the Sn nanoclusters in nitrogen-doped carbon polyhedra (Sn x NC) surpassed the electrocatalytic perform-ance of Sn single atom catalyst for acidic oxygen reduction reaction, owing to the favorable oxygen species adsorption. Therefore, designing Pt-based electrocatalyst with sub-nanometer size would boost the reaction kinetics and achieve unexpected catalytic performance.…”