ChemRxiv
These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
1/1
0/0

Unifying the Alkaline Hydrogen Evolution/oxidation Reactions Kinetics by Identifying the Roles of Hydroxyl-Water-Cation Adducts

preprint
submitted on 26.09.2018 and posted on 27.09.2018 by Ershuai Liu, Jingkun Li, Li Jiao, Huong Thi Thanh Doan, Zeyan Liu, Zipeng Zhao, Yu Huang, Kuzhikalail. M. Abraham, Sanjeev Mukerjee, Qingying Jia
Despite the fundamental and practical significance of the hydrogen evolution and oxidation reactions (HER/HOR), their kinetics in base remain unclear. Herein, we show that the alkaline HER/HOR kinetics can be unified by the catalytic roles of the adsorbed hydroxyl (OHad)-water-alkali metal cation (AM+) adducts, on the basis of the observations that enriching the OHad abundance via surface Ni benefits the HER/HOR; increasing the AM+ concentration only promotes the HER while varying the identity of AM+ affects both HER/HOR. The presence of OHad-(H2O)x-AM+ in the double layer region facilitates the OHad removal into the bulk forming OH--(H2O)x-AM+ as per the hard-soft acid-base (HSAB) theory, thereby selectively promoting the HER. It can be detrimental to the HOR as per the bifunctional mechanism as the AM+ destabilizes the OHad, which is further supported by the CO oxidation results. This new notion may be important for alkaline electrochemistry.

History

Email Address of Submitting Author

liu.ers@husky.neu.edu

Institution

Northeastern University

Country

United States

ORCID For Submitting Author

0000-0002-6491-5504

Declaration of Conflict of Interest

The authors declare no competing financial interests.

Exports

Logo branding

Exports