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.

Modulating Electronic Environment of Ru Nanoclusters via Local Charge Transfer for Accelerating Alkaline Water Electrolysis

“…In addition, compared with a zero-band gap at the Fermi level in Ru nc -C x , the Ru nc -N x has a continuous and higher state density at the Fermi level, which gives Ru nc -N x higher electron transfer ability and reactivity. [41] Thereafter, the water dissociation process was carefully calculated to reveal the intrinsic high alkaline HER activity of Ru nc -N x . As shown in Figure 4c, the molecular H 2 O is adsorbed on the Ru cluster in Ru nc -N x at the initial stage (IS).…”

“…In addition, compared with a zero‐band gap at the Fermi level in Ru nc ‐C x , the Ru nc ‐N x has a continuous and higher state density at the Fermi level, which gives Ru nc ‐N x higher electron transfer ability and reactivity. [ 41 ]…”

“…[31,32] Charge transfer, as a typical strong metal-support interaction occurring at the interface between a metal nanoparticle and support, can also introduce significant electronic environment modulation on metal atoms and directly influence their catalytic behaviors, [33] which has been demonstrated to be a facile and efficient strategy to enhance the catalytic activity of noble metals. [34][35][36][37] However, up to now, rarely studies have taken the charge transfer strategy to tune the electronic structure and bond environments of Ru nanoclusters-based catalysts, [38][39][40][41] which is of great importance to be discovered for the future design of optimal Ru catalysts.…”

Coordination Manipulation of Single Atom Catalysts for Lithium‐Sulfur Batteries: Advances and Prospects

“…[59,60] According to the Lewis acidbase theory, metal centers are in favor of binding with S species, rendering stronger adsorption. In addition, tuning the coordination environment can enrich the types of SACs, [61,62] which is conducive to the design of efficient electrocatalysts for LiÀ S batteries. To better explore the modulated dispersion and structure of SACs, a wealth of advanced characterizations involving high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) [63][64][65] , X-ray absorption nearedge structure (XANES), [66,67] extended X-ray absorption fine structure (EXAFS), [68] and time-of-flight secondary ion mass spectrometry (TOF-SIMS) [69] have been employed.…”

Multifaceted Catalytic ROS‐Scavenging via Electronic Modulated Metal Oxides for Regulating Stem Cell Fate

“…[23,24] Designing metal oxides for efficient ROS-scavenging has been extremely limited due to their high oxidation states of metal centers originating from coordinated electronegative atoms, which also deteriorate the redox properties of metal centers. [9,[25][26][27][28] Thus, it is essential to search for suitable strategy to overcome the unbalanced valance states during catalytic ROS-scavenging and achieve reversible catalytic cycles with high kinetics. [29][30][31] Among various metal oxides, Co 3 O 4 is considered one of the most potential candidates for catalytic ROS-scavenging because of the high redox potential of Co 3+ /Co 2+ .…”