Tailoring Bond Microenvironments and Reaction Pathways of Single‐Atom Catalysts for Efficient Water Electrolysis

Abstract

Single-atom sites (SASs) are commonly stabilized and influenced by neighboring atoms in the host; disclosing the structure-reactivity relationships of SASs in water electrolysis is one of the grand challenges originating from the tremendous wealth of support materials with complex structures. Through a multidisciplinary view of the design principles, synthesis strategies, characterization techniques, and theoretical analysis of structure-performance correlations, this timely Review is dedicated to summarizing the most recent progress in tailoring bond microenvironments on different supports and discussing the reaction pathways and performance advantages of different SAS structures for water electrolysis. The essence and mechanisms of how SAS structures influence electrocatalysis and the critical requirements for future developments are discussed. Finally, the challenges and perspectives are also provided to stimulate the practical, widespread utilization of SAS catalysts in water-splitting electrolyzers.

Wood Derived Flexible and Spongy Architectures for Advanced Electrochemical Energy Storage and Conversion

“…Energy changes at the d‐band center of metal atoms may be affected by the efficient charge transfer between the SACs and the local coordination environment of the support. [ 103 ] By changing the number and type (coordination number and element type) of the nearby coordination species in the anchoring sites (first coordination shell) ( Figure a), it is possible to change the shape and electronic structure of metal centers. [ 104 ] Moreover, the vicinal species beyond the first shell of a single metal center can also modulate the electronic structure to optimize the catalytic performance (Figure 6b).…”

Edge-Site Co–Nx Model Single-Atom Catalysts for CO2 Electroreduction

“…1,2 The transition metal−nitrogen−carbon (M−N−C) type single-atom catalyst is an important family of non-noble metal-based electrocatalysts widely used in the CO 2 reduction reaction (CO 2 RR), 3,4 the O 2 reduction reaction (ORR), 5 and other electrocatalytic processes. 6 The most widely used methods to prepare M−N−C catalysts are the pyrolysis of metal organic precursors. 7,8 The M−N−C catalysts derived from this method are typically porous and amorphous and usually contains different types of N sites, such as pyrrolic, 9 pyridinic, 10 and graphitic N atoms, 11 and different single-atom metal sites, such as in-plane M−N 4 sites, 12 edge M−N x (x = 2, 13 3, 14 and 4 15 ) sites, etc., as illustrated in Figure 1a.…”