Single Atom Catalysts: An Overview of the Coordination and Interactions with Metallic Supports

Abstract

Catalyst utilization is a key economic factor in heterogeneous catalysis, particularly, when noble metals are used as the active phase. A huge saving on catalyst cost can be achieved with developing a single atomic layer of the active catalyst on a given cheap support. Besides the economic benefit, single atom catalysts (SACs) have also shown superior activity and selectivity relative to catalytic particles or nanoparticles; yet they are prone to aggregation and deactivation. The development of effective, stable, and commercially viable SACs is still a huge challenge. One of the remaining key obstacles is the ability to easily and effectively tune SACs‐support interactions and coordination in a way that enables the production of robust, stable, and versatile SACs. Accordingly, the coordination and interactions between metallic supports and SACs and their impacts on SACs stability and activity are reviewed in this article.

Rational Design of Heterogeneous Dual-Atom Catalysts for CO2 Electroreduction Reactions

“…Geometrical defects and vacancies, generated at high temperatures, can form coordinating sites to metal atoms (M−π interactions) and new active sites for electrocatalytic reduction reactions . Several review papers were published recently on the electrocatalytic applications of SACs. ,,− …”

Metal-related electrocatalysts for Li–CO2batteries: an overview of the fundamentals to explore future-oriented strategies

“…Although SACs can be considered the “holy grail” of catalysts, they also have the disadvantage that when the metal particles are reduced to the single-atom level, the specific surface area increases dramatically, resulting in a dramatic increase in the free energy of the metal surface, which can easily lead to agglomerative coupling and the formation of large clusters during preparation and reaction, thus leading to catalyst deactivation. 193 Based on this, the current very cutting-edge solution strategy is to combine SACs with another legendary structure, MOFs, which will surely further solve the above problem. Next, the application of MOFs in Li–CO 2 batteries will be further outlined, and the related innovative work of combining MOFs with SACs will also be highlighted.…”

Oxidative dehydrogenation of cyclohexene on atomically precise subnanometer Cu4−nPdn (0 ≤ n ≤ 4) tetramer clusters: the effect of cluster composition and support on performance

“…26 Supported single atoms and subnanometer clusters of transition metals have proven to be promising catalysts in various reactions, including CO 2 hydrogenation, the Fischer-Tropsch reaction and the hydrogenation/dehydrogenation of hydrocarbons. [27][28][29][30][31][32][33][34] Thanks to the small size of the cluster, usually less than 50 atoms, quantum effects occur. 35 By comparison with the bulk material, smaller clusters tend to have discrete electron levels and, as a result, they lose their metallic character and resemble isolated molecules, with their electronic (as well as geometric) structure altered by adding a single atom of the same or a different metal.…”

“…Oxides, as well as carbon-based materials, are widely used materials for supporting metal clusters. 28 The nature of the support plays an important role in determining the properties of clusters via cluster-support interactions, 49 inuencing the electronic structure and shape of the clusters, 45 charge distribution inside the cluster and the charge transfer between the cluster and the support, 50 all of which can strongly affect the catalytic properties. 20,40,[51][52][53] The choice of substrate provides one of the control knobs for tuning the performance of the catalyst.…”