Single-Atom Engineering to Ignite 2D Transition Metal Dichalcogenide Based Catalysis: Fundamentals, Progress, and Beyond

Abstract

Single-atom catalysis has been recognized as a pivotal milestone in the development history of heterogeneous catalysis by virtue of its superior catalytic performance, ultrahigh atomic utilization, and well-defined structure. Beyond single-atom protrusions, two more motifs of single-atom substitutions and single-atom vacancies along with synergistic single-atom motif assemblies have been progressively developed to enrich the single-atom family. On the other hand, besides traditional carbon material based substrates, a wide variety of 2D transitional metal dichalcogenides (TMDs) have been emerging as a promising platform for single-atom catalysis owing to their diverse elemental compositions, variable crystal structures, flexible electronic structures, and intrinsic activities toward many catalytic reactions. Such substantial expansion of both single-atom motifs and substrates provides an enriched toolbox to further optimize the geometric and electronic structures for pushing the performance limit. Concomitantly, higher requirements have been put forward for synthetic and characterization techniques with related technical bottlenecks being continuously conquered. Furthermore, this burgeoning single-atom catalyst (SAC) system has triggered serial scientific issues about their changeable single atom−2D substrate interaction, ambiguous synergistic effects of various atomic assemblies, as well as dynamic structure−performance correlations, all of which necessitate further clarification and comprehensive summary. In this context, this Review aims to summarize and critically discuss the single-atom engineering development in the whole field of 2D TMD based catalysis covering their evolution history, synthetic methodologies, characterization techniques, catalytic applications, and dynamic structure−performance correlations. In situ characterization techniques are highlighted regarding their critical roles in real-time detection of SAC reconstruction and reaction pathway evolution, thus shedding light on lifetime dynamic structure−performance correlations which lay a solid theoretical foundation for the whole catalytic field, especially for SACs.

Single‐Atom‐Regulated Heterostructure of Binary Nanosheets to Enable Dendrite‐Free and Kinetics‐Enhanced Li–S Batteries

“…It suggests that Pt SAs are successfully anchored on In 2 S 3 nanosheets, which is further confirmed by the red‐shift of the Raman peak of In 2 S 3 for the Pt SAs/In 2 S 3 /Ti 3 C 2 sample compared with those of the In 2 S 3 /Ti 3 C 2 and In 2 S 3 counterparts (Figure S2a, Supporting Information). [ 15b ] However, no Raman peak shift of Ti 3 C 2 can be observed for Pt SAs/In 2 S 3 /Ti 3 C 2 (Figure S2a, Supporting Information), implying the inexistence of Pt SAs in Ti 3 C 2 supports. [ 6c,d ] The XRD pattern of the Pt SAs/In 2 S 3 /Ti 3 C 2 compared with those of the Ti 3 C 2 , In 2 S 3 and In 2 S 3 /Ti 3 C 2 counterparts in Figure S2b, Supporting Information, indicates that no crystalline Pt existed in the sample.…”

“…and their heterostructure interfaces, enabling kinetic enhancement of electrocatalytic reactions. [ 15 ] In addition, some research works have shown that the high polarity of SACs anchored on TMCs/heterostructures could expose more active sites, resulting in accelerated kinetics of polysulfide conversion in electrochemical processes and significantly suppressed uneven deposition of lithium metal. [ 14a,16 ] Typically, SACs‐anchored TMCs/heterostructures are synthesized by methods such as high temperature migration/pyrolysis, impregnation/ion‐exchange/coprecipitation, atomic layer deposition, and electrochemical reduction.…”

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

“…TM dichalcogenides (TMDs) are other important LD materials for single atom and atomic cluster catalysts because of their variable elemental compositions, flexible electronic structures, diverse crystal structures, and intrinsic activities toward many catalytic reactions. [ 185 ] Li et al reported a single Co atom distributed on 2H‐MoS 2 surfaces catalysts for hydrodeoxygenation (HDO) reactions (Figure 11B). [ 168 ] DFT calculations show that the formation of metal vacancy interfaces on the MoS 2 surface can promote the H 2 activation on the reactive single Co atom.…”

Recent strategies for activating the basal planes of transition metal dichalcogenides towards hydrogen production

“…33 Based on current achievements, it is time to offer a critical review of this topic, potentially arousing a wide range of readers for the future development of this eld. Note that some excellent reviews have already been published based on 2D TMDCs for HER, 31,[34][35][36][37][38][39] while there is still a lack of summaries focusing only on the basal plane and its activating strategies for HER.…”