Atomically Dispersed Heteronuclear Dual‐Atom Catalysts: A New Rising Star in Atomic Catalysis

Abstract

carbon dioxide reduction, which can also be driven by clean and renewable energies such as wind, solar and hydropower resources, represent crucial steps of these renewable energy devices. However, the performances of these chemical reactions strongly rely on the energy storage and conversion efficiencies of the catalytic materials deposited on the electrodes. [6][7][8][9][10] Therefore, the development of robust and earth-abundant catalysts with both high catalytic activity and selectivity play a critical role in the real application of these devices.Current catalysts for energy-related chemical reactions are heavily dependent on noble metals, which impedes their large potential commercialization. [11][12][13] Further, the catalytic process mostly occurred on the metal surfaces, leading to the very low utilization efficiency of the catalysts. To minimize the waste of the non-accessible atoms in the bulk metals, researchers developed several strategies to modify metal structures in order to expose as many metal atoms as possible. [10,[14][15][16][17][18] One of the most popular methods is to downsize the solid metal catalysts to the atomic level (Figure 1). More interestingly, the catalytic behaviors of the metal catalysts with different sizes have significantly Atomic catalysts (AC) are gaining extensive research interest as the most active new frontier in heterogeneous catalysis due to their unique electronic structures and maximum atom-utilization efficiencies. Among all the atom catalysts, atomically dispersed heteronuclear dual-atom catalysts (HDACs), which are featured with asymmetric active sites, have recently opened new pathways in the field of advancing atomic catalysis. In this review, the up-todate investigations on heteronuclear dual-atom catalysts together with the last advances on their theoretical predictions and experimental constructions are summarized. Furthermore, the current experimental synthetic strategies and accessible characterization techniques for these kinds of atomic catalysts, are also discussed. Finally, the crucial challenges in both theoretical and experimental aspects, as well as the future prospects of HDACs for energy-related applications are provided. It is believed that this review will inspire the rational design and synthesis of the new generation of highly effective HDACs.

Experimental and Theoretical Advances on Single Atom and Atomic Cluster‐Decorated Low‐Dimensional Platforms towards Superior Electrocatalysts

“…[106,107] Furthermore, density functional theory (DFT) calculations have been very useful to study the electrocatalytic active sites, thus enhancing our knowledge about the electrocatalytic pathways on the surfaces of ACEs. [1,108,109] Most importantly, the structural control of the metallic clusters of ACEs is becoming a new strategy to finely tune the reactivity and, in turn, the intrinsic catalytic properties of their catalytically active centers, thus promoting the activation of ultractive hot spots for different electrocatalytic processes. [8,79] Nanocarbon platforms with different dimensionalities have been used to support different types of atomic clusters, thus regulating a bunch of ion migration processes together with the energetic levels of adsorbed intermediate catalytic species in key catalytic reactions like oxygen reduction reaction (ORR), oxygen evolution reaction (OER), nitrogen reduction reaction (NRR) and CO 2 electroreduction reaction (CO 2 RR).…”

“…[137] The understanding of the structure-catalytic function relationships of SACs has been thoroughly investigated in the recent years. [1,109,138] Nonetheless, there is a lack of knowledge about the proximity effects of neighboring single metal atoms for ORR, HER, and OER reactions, which have been limited the design of more powerful atomic electrocatalysts due to the lack of details on the intrinsic activity of individual atomic sites and the mass transport of intermediate species. Fortunately, Guihao Yu and coworkers have elegantly reported a comprehensibly microscopic, electrochemical, spectroscopic, and theoretical study about the connection between the atomic distribution density of Fe-N 4 SACs and their resulting ORR electrocatalytic rates.…”

“…Moreover, heterogenous dimer atomic clusters have been emerging as a new class of electrocatalysts with improved catalytic performance. [109] The asymmetry active sites can work synergistically in the reaction and the activity and selectivity can be tuned by selecting appropriate combinations. [161][162][163] The electronic properties of subnanometer atomic clusters can also be modified by tuning the size of the atoms.…”

“…Figuring out the interaction between the atomic cluster and the substrates could guide the rational design of highly efficient catalysts. [109,171,172] Carbon-based LD materials including graphene, [173][174][175] graphdiyne (GDY), [176][177][178] g-C 3 N 4 , [11,179,180] CN [181][182][183] and their derivatives have attracted huge interests in designing various electrocatalysts. The electronic properties of atomic clusters could be modified by loading on different substrates.…”

“…[ 106,107 ] Furthermore, density functional theory (DFT) calculations have been very useful to study the electrocatalytic active sites, thus enhancing our knowledge about the electrocatalytic pathways on the surfaces of ACEs. [ 1,108,109 ]…”