Mesoporous WCx Films with NiO‐Protected Surface: Highly Active Electrocatalysts for the Alkaline Oxygen Evolution Reaction. Issue 21 (8th September 2021)

• Record Type: Journal Article
• Authors: Frisch, Marvin; Ye, Meng‐Yang; Hamid Raza, Muhammad; Arinchtein, Aleks; Bernsmeier, Denis; Gomer, Anna; Bredow, Thomas; Pinna, Nicola; Kraehnert, Ralph
• Is Part Of: ChemSusChem. Volume 14:Issue 21(2021)
• Page Start: 4708
• Page End: 4717
• Publication Date: 2021-09-08
• Subjects: atomic layer deposition -- electrocatalysis -- metal carbides -- mesoporous materials -- nickel; Green chemistry -- Periodicals; Sustainable engineering -- Periodicals; Chemistry -- Periodicals; Chemical engineering -- Periodicals; 660
• DOI: 10.1002/cssc.202101243
• Languages: English
• ISSNs: 1864-5631

Abstract

Abstract: Metal carbides are promising materials for electrocatalytic reactions such as water electrolysis. However, for application in catalysis for the oxygen evolution reaction (OER), protection against oxidative corrosion, a high surface area with facile electrolyte access, and control over the exposed active surface sites are highly desirable. This study concerns a new method for the synthesis of porous tungsten carbide films with template‐controlled porosity that are surface‐modified with thin layers of nickel oxide (NiO) to obtain active and stable OER catalysts. The method relies on the synthesis of soft‐templated mesoporous tungsten oxide (mp. WO x ) films, a pseudomorphic transformation into mesoporous tungsten carbide (mp. WC x ), and a subsequent shape‐conformal deposition of finely dispersed NiO species by atomic layer deposition (ALD). As theoretically predicted by density functional theory (DFT) calculations, the highly conductive carbide support promotes the conversion of Ni 2+ into Ni 3+, leading to remarkably improved utilization of OER‐active sites in alkaline medium. The obtained Ni mass‐specific activity is about 280 times that of mesoporous NiO x (mp. NiO x ) films. The NiO‐coated WC x catalyst achieves an outstanding mass‐specific activity of 1989 A gNi −1 in a rotating‐disc electrode (RDE) setup at 25 °C using 0.1 m KOH as the electrolyte. Abstract : ALD‐fashioned : A highly active and stable electrocatalyst for the alkaline oxygen evolution reaction based on a mesoporous tungsten carbide film surface‐modified with a conformal NiO layer by atomic layer deposition is presented. The electrocatalyst reaches a record high mass activity of 1989 A gNi −1 in 0.1 m KOH electrolyte, which is more than 280 times higher than that of a mesoporous NiO x film.