Single Atomic Vacancy Catalysis

Abstract

Single atom catalysts provide exceptional activity. However, measuring the intrinsic catalytic activity of a single atom in real electrochemical environments is challenging. Here, we report the activity of a single vacancy for electrocatalytically evolving hydrogen in two-dimensional (2D) MoS2. Surprisingly, we find that the catalytic activity per vacancy is not constant but increases with its concentration, reaching a sudden peak in activity at 5.7 × 1014 cm–2 where the intrinsic turn over frequency and Tafel slope of a single atomic vacancy was found to be ∼5 s–1 and 44 mV/dec, respectively. At this vacancy concentration, we also find a local strain of ∼3% and a semiconductor to metal transition in 2D MoS2. Our results suggest that, along with increasing the number of active sites, engineering the local strain and electrical conductivity of catalysts is essential in increasing their activity.

Synthesis of Ultrahigh‐Quality Monolayer Molybdenum Disulfide through In Situ Defect Healing with Thiol Molecules

“…Noteworthily, we have compared the SV density of LCVD MoS 2 with MoS 2 grown by conventional CVD method with solid precursors and the exfoliated MoS 2 (Figure 3f). The SV density of monolayer MoS 2 grown by LCVD is the lowest among all reported CVD‐grown samples, [ 17,32–36 ] and close to the exfoliated one (0.15 nm −2 ; Figure S7, Supporting Information). Besides, it is worth mentioning that all the point defects are mono‐SV, which is different from previous reports of SCVD‐grown MoS 2 where disulfur vacancies are usually observed.…”

“…Besides, it is worth mentioning that all the point defects are mono‐SV, which is different from previous reports of SCVD‐grown MoS 2 where disulfur vacancies are usually observed. [ 17,34,36 ]…”

Defects in nanosilica catalytically convert CO 2 to methane without any metal and ligand

“…The CO 2 methanation process needed metal-based catalysts (1)(2)(3)(4). CO 2 hydrogenation was also achieved by metal/metal oxide hybrids and metal hydrides (1,(5)(6)(7)(8)(9)(10)(11)(12). CO 2 polymerization was although reported by metal-free catalysts (13).…”

“…Thus, there is an urgent need to discover and develop a heterogeneous catalyst which is highly active, selective, and stable. It is well-known that the presence of various defects in nanomaterials endows them with a variety of functions (2,8,(14)(15)(16)(17)(18). However, the ability to control and tune the type, concentration, and distribution of the various defects on the surface of nanomaterials is a considerable challenge.…”

Visualizing reactant molecules induced lattice breath of catalyst and its role for activity enhancement

“…1b and 1c), the smooth and regular atomic arrangement in the crystal lattice of WO 3 became rougher and distorted after the introduction of defects 16 . Moreover, compared to the quantity of Pt loading on WO 3-x and WO 3 (Supplementary Table 2), it was inferred that existence of oxygen vacancy in the WO 3-x greatly improved the anchoring of isolated Pt atoms [17][18][19] . Besides, XAS was also carried to study the coordination environment of isolated Pt.…”