Atomic‐Level Interface Engineering for Boosting Oxygen Electrocatalysis Performance of Single‐Atom Catalysts: From Metal Active Center to the First Coordination Sphere

Abstract

Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are the core reactions of a series of advanced modern energy and conversion technologies, such as fuel cells and metal-air cells. Among all kinds of oxygen electrocatalysts that have been reported, single-atom catalysts (SACs) offer great development potential because of their nearly 100% atomic utilization, unsaturated coordination environment, and tunable electronic structure. In recent years, numerous SACs with enriched active centers and asymmetric coordination have been successfully constructed by regulating their coordination environment and electronic structure, which has brought the development of atomic catalysts to a new level. This paper reviews the improvement of SACs brought by atom-level interface engineering. It starts with the introduction of advanced techniques for the characterizations of SACs. Subsequently, different design strategies that are applied to adjust the metal active center and first coordination sphere of SACs and then enhance their oxygen electrocatalysis performance are systematically illustrated. Finally, the future development of SACs toward ORR and OER is discussed and prospected.

Geometric and Electronic Engineering of Atomically Dispersed Copper‐Cobalt Diatomic Sites for Synergistic Promotion of Bifunctional Oxygen Electrocatalysis in Zinc–Air Batteries

“…[23,24] Recent research findings demonstrate that the intrinsic activity of SACs can be further enhanced by altering the coordination environments and electronic properties of active sites through non-metal heteroatom doping (B, N, O, S, P, etc.). [16,[25][26][27][28][29] Another effective approach is to construct SAs with two different transition metals through the synergetic effect of dual-metal sites to modulate the electrocatalysts' activity. [30][31][32][33][34][35][36][37][38] Such an approach takes advantage of the two isolated metal sites by pairing or long-range coupling to modulate the coordination and electronic structures, which correlates with the adsorption/desorption behavior of relevant oxygen intermediates.…”

Experimentally revealed and theoretically certified synergistic electronic interaction of V-doped CoS for facilitating the oxygen evolution reaction

“…23 Based on this current situation, herein, we report a universal strategy for the preparation of an electrochemically-activated CoS-based nanocatalyst doped with V and Mo elements at the oil–water interface via a one-pot solvothermal process. 24 The as-prepared VCoS has remarkable OER performance, which is related to the significant effect of oxygen vacancies introduced by the insertion of V on the electrical properties. As expected, VCoS with a low overpotential of η 10 = 255 mV and a small Tafel slope of 155 mV dec −1 , which is close to the almost state-of-the-art RuO 2 (254 mV, 10 mA cm −2 ).…”

The rational design of high-performance graphene-based single-atom electrocatalysts for the ORR using machine learning

“…3–6 Due to the high atom utilization, high surface area and atomically dispersed active sites, single-atom catalysts (SACs) could be potential high-performance electrocatalysts. 7–12 To improve the electroconductivity of SACs, graphene is usually the substrate, which also has rich active sites. 13,14 Related high-performance SACs have been reported by numerous studies.…”