A WOx mediated interface boosts the activity and stability of Pt-catalyst for alkaline water splitting

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2022-03, Vol.431, p.133287, Article 133287
• Main Authors: Yin, Di, Cao, Yun-Dong, Chai, Dong-Feng, Fan, Lin-Lin, Gao, Guang-Gang, Wang, Ming-Liang, Liu, Hong, Kang, Zhenhui
• Format: Article
• Language: English
• Subjects: Alkaline water splitting; Bifunctional electrocatalysts; Nanodot; Polyoxometalate; WOx interface
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2021.133287

The highly efficient and stable Pt-WO3−x@rGO bifunctional catalyst was synthesized from structure-defined Pt-substituted polyoxometalate. In this catalyst, a WOx mediated interface (Pt0⋅⋅⋅O−W) plays a key role to enhance the electron transfer and reduce the activation energy for both HER and OER. [Display omitted] •Pt-WO3−x@rGO shows low overpotentials of 37 mV for HER and 174 mV for OER.•Pt-WO3−x@rGO achieves working voltage of 1.55 V (10 mA cm−2) for water splitting in alkalinity.•WOx mediated interface plays a key role to enhance electron transfer and reduce activation energy.•WOx mediated interface enhances the Pt based catalyst stability in alkalinity. Water splitting offers a clean way to produce hydrogen, in which, an efficient catalyst interface is one of the key factors to boot the activity and stability. Here, using polyoxotungstate (POT) as precursor, Pt-based bifunctional catalysts were fabricated, which are composed of Pt, WOx and graphene (Pt-WO3−x@rGO). The Pt-WO3−x@rGO (1.58% Pt-loading) catalyst shows an enhanced catalytic activity, namely, overpotentials of 37 mV for Hydrogen evolution reaction (HER) and 174 mV for Oxygen evolution reaction (OER), and achieves a working voltage of 1.55 V at 10 mA cm−2 for water splitting in alkaline-medium. Electrochemical analyses and DFT calculation suggest that the WOx mediated interface (Pt0⋅⋅⋅O − W) plays a key role to enhance the electron transfer and reduce the activation energy for both HER and OER. Moreover, this kind of Pt0⋅⋅⋅O − W interface enhances the Pt based catalyst stability in alkaline-medium significantly.