Proton Conduction over the Zeolite with Surface Water Cluster for the Water Electrolysis at Neutral Condition

• Published in: ChemCatChem 2024-02, Vol.16 (4), p.n/a
• Main Authors: Tashiro, Keigo, Saito, Taisei, Goto, Kojiro, Masuda, Junki, Miyakage, Takumi, Shimoda, Shuhei, Toyao, Takashi, Tsunoji, Nao, Shimizu, Ken‐ichi, Matsumoto, Hiroshige, Satokawa, Shigeo
• Format: Article
• Language: English
• Subjects: Chemical bonds; Clusters; Electrolysis; Electrolytic cells; High temperature; Hydrogen production; Hydrophilicity; Hydrophobicity; Proton conduction; silanol nest; Surface water; Water chemistry; water cluster; water electrolysis; zeolite; Zeolites
• ISSN: 1867-3880; 1867-3899
• DOI: 10.1002/cctc.202301297

Electrolytic hydrogen production from water at neutral pH was achieved by using novel proton (H+) conduction system assisted by zeolite. Experimental and computational insights demonstrated that defective silanol nest generated by dealumination played an important role in the formation of water clusters and the H+ conduction over the zeolites proceeded via exchange of H‐bonding between water molecules in the cluster. In addition, a proper balance between hydrophilicity and hydrophobicity is required for effective H+ conduction and silanol nest afford the balance. Furthermore, the contribution of hydrophilicity of the zeolite for the adsorption of water molecules became more drastic at high temperatures. Water electrolysis efficiency was strongly dependent on the H+ conductivity over the beta‐type zeolite. The electrolytic cell containing the zeolite has the potential to be applied to the new hydrogen production system. A novel H+ conductive system assisted by a dealuminated zeolite aiming to water electrolysis at neutral condition was presented. Silanol nests on zeolite surface formed by dealumination act as both water adsorption site and pillar for the formation of water cluster, and H+ migrated via exchanging of hydrogen bonding between water with closer distance than balk one. Additionally, water electrolysis at neutral pH was successfully achieved.