Search

Downsizing a catalyst nanoparticle (NP) to a single atom (SA) has proven to be highly effective in increasing catalytic activity and decreasing the amount of catalyst required for various electrochemical reactions. However, insufficient stability of the single‐atom site catalysts (SACs) is still a significant challenge for their practical application. Here, SACs firmly bound to stable metal oxide NPs are proposed to dramatically increase the electrochemical activity and stability of SA‐based catalysts for hydrogen evolution reaction (HER). Starting from a Ru‐infiltrated, Zr‐based metal‐organic framework (MOF), the tetragonal zirconium oxide (ZrO2‐x) NPs‐embedded carbon matrix is fabricated as support through facile pyrolysis. Simultaneously, Ru SAs as active sites are well dispersed on the surface of ZrO2‐x NPs due to the generation of oxygen vacancies in the tetragonal ZrO2‐x. The Ru‐ZrO2‐x SAC exhibits a 4–5 times higher mass activity than commercial Pt and Ru catalysts and superior durability due to strong metal‐support interaction (SMSI) between Ru atoms and ZrO2‐x substrate. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlight • Practical growth for 2D MoS 2 -graphene heterostructure (MGH) was introduced. • Low-temperature sulfurization of Mo thin film was realized by H 2 S plasma. • As-grown MoS 2 film on graphene naturally contains large number of active sites. • The MGH was shown enhanced electrocatalytic performance. Abstract In this study, we successfully demonstrate the fabrication of a MoS 2 -graphene heterostructure (MGH) on a 4 inch wafer at 300 °C by depositing a thin Mo film seed layer on graphene followed by sulfurization using H 2 S plasma. By utilizing Raman spectroscopy and high-resolution transmission electron microscopy, we have confirmed that 5–6 MoS 2 layers with a large density of sulfur vacancies are grown uniformly on the entire substrate. The chemical composition of MoS 2 on graphene was evaluated by X-ray photoelectron spectroscopy, which confirmed the atomic ratio of Mo to S to be 1:1.78, which is much lower than the stoichiometric value of 2 from standard MoS 2. To exploit the properties of the nanocrystalline and defective MGH film obtained in our process, we have utilized it as a catalyst for hydrodesulfurization and as an electrocatalyst for the hydrogen evolution reaction. Compared to MoS 2 grown on an amorphous SiO 2 substrate, the MGH has smaller onset potential and Tafel slope, indicating its enhanced catalytic performance. Our practical growth approach can be applied to other two-dimensional crystals, which are potentially used in a wide range of applications such as electronic devices and catalysis. [ABSTRACT FROM AUTHOR]

The cover art depicts the strong interaction between single-atom site Ru catalysts and chemically stable ZrO SB 2-x sb nanoparticles, enabling superior stability and improved activity of the catalysts for hydrogen evolution reactions. Hydrogen evolution reaction, metal-organic frameworks, metal-support interactions, oxygen-deficient zirconia, reconstruction engineering, Ru catalysts, single-atom sites catalysts Keywords: hydrogen evolution reaction; metal-organic frameworks; metal-support interactions; oxygen-deficient zirconia; reconstruction engineering; Ru catalysts; single-atom sites catalysts EN hydrogen evolution reaction metal-organic frameworks metal-support interactions oxygen-deficient zirconia reconstruction engineering Ru catalysts single-atom sites catalysts 1 1 1 07/21/23 20230718 NES 230718 B Single-Atom Sites Catalysts b In article number 2300673, Dongmok Whang, Sung Jong Yoo, Namgee Jung, Joseph T. Hupp, and co-workers present a strategy to enhance the efficiency and durability of sub-nanometer catalysts for electrochemical reactions. [Extracted from the article]