Improving the HER activity and stability of Pt nanoparticles by titanium oxynitride support

Autor: Smiljanić, Milutin, Panić, Stefan, Bele, Marjan, Ruiz-Zepeda, Francisco, Pavko, Luka, Gašparič, Lea, Kokalj, Anton, Gaberšček, Miran, Hodnik, Nejc
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: ACS catalysis, vol. 12, no. 20, 2022.
ACS Catalysis
ISSN: 2155-5435
Popis: Water electrolysis powered by renewables is regarded as the feasible route for the production of hydrogen, obtained at the cathode side through electrochemical hydrogen evolution reaction (HER). Herein, we present a rational strategy to improve the overall HER catalytic performance of Pt, which is known as the best monometallic catalyst for this reaction, by supporting it on a conductive titanium oxynitride (TiON$_x$) dispersed over reduced graphene oxide nanoribbons. Characterization of the Pt/TiON$_x$ composite revealed the presence of small Pt particles with diameters between 2 and 3 nm, which are well dispersed over the TiON$_x$ support. The Pt/TiON$_x$ nanocomposite exhibited improved HER activity and stability with respect to the Pt/C benchmark in an acid electrolyte, which was ascribed to the strong metal−support interaction (SMSI) triggered between the TiON$_x$ support and grafted Pt nanoparticles. SMSI between TiON$_x$ and Pt was evidenced by X-ray photoelectron spectroscopy (XPS) through a shift of the binding energies of the characteristic Pt 4f photoelectron lines with respect to Pt/C. Density functional theory (DFT) calculations confirmed the strong interaction between Pt nanoparticles and the TiON$_x$ support. This strong interaction improves the stability of Pt nanoparticles and weakens the binding of chemisorbed H atoms thereon. Both of these effects may result in enhanced HER activity.
Databáze: OpenAIRE
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