Surface-functionalized three-dimensional MXene supports to boost the hydrogen evolution activity of Pt catalysts in alkaline media

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2023-03, Vol.11 (1), p.5328-5336
• Main Authors: Hong, Haeji, Kim, Ho Young, Cho, Won Il, Song, Ho Chang, Ham, Hyung Chul, Chae, Kyunghee, Marques Mota, Filipe, Kim, Jin Young, Kim, Dong Ha
• Format: Article
• Language: English
• Subjects: Alkaline water; Catalysts; Density functional theory; Electrolysis; Green hydrogen; Hydrogen; Hydrogen evolution reactions; Hydrogen production; MXenes; Nanoparticles; Stability analysis
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/d2ta08852e

Alkaline water electrolysis is the most promising technology for green-hydrogen production, which is considered a cornerstone of carbon-neutral energy society. In the development of functional catalysts able to overcome the sluggish kinetics of the alkaline hydrogen evolution reaction (HER), MXenes emerge as attractive support candidates with distinctive hydrophilicity, high conductivity, and high (electro)chemical stability. Herein, we assess the promise of three-dimensionally interconnected Ti 3 C 2 T x MXenes with distinct surface terminations (-O, -OH, and -F) as efficient support materials for Pt-loaded alkaline HER catalysts. In particular, our OH-functionalized Pt/Ti 3 C 2 (OH) x shows the highest HER activity (30 mV dec −1 ), unlocking a competitive performance against the Pt/C reference (61 mV dec −1 ) and benchmark literature reports. The outstanding performance is ascribed to the cooperative effects of the extended MXene surface area and established interactions between Pt and Ti(OH) x surface centers. In parallel, the oxophilic nature of Ti 3 C 2 (OH) x facilitates Pt dispersion, presumably playing a key role in the extended catalytic stability here reported. The superior activity is further substantiated by density functional theory calculations, with the modeled Pt/Ti 3 C 2 (OH) 2 unveiling a significantly higher onset potential and the weakest hydrogen binding energy over supported Pt nanoparticles (−2.51 eV) against both -O (−2.72 eV) and -F (−3.15 eV) functionalized counterparts. Distinctive surface functional groups on 3D MXenes as Pt-supports are correlated with optimized Pt-H affinity and HER activity in alkaline media.