XPS Investigation on Improving Hydrogen Sorption Kinetics of the KSiH3 System by Using Zr-Based Catalysts

Anish Tiwari; Shivani Agarwal; Kriti Shrivastava; Takayuki Ichikawa; Ankur Jain; Rini Singh

doi:10.3390/ma15217454

XPS Investigation on Improving Hydrogen Sorption Kinetics of the KSiH₃ System by Using Zr-Based Catalysts

Materials (Basel). 2022 Oct 24;15(21):7454. doi: 10.3390/ma15217454.

Authors

Anish Tiwari¹, Shivani Agarwal², Kriti Shrivastava¹, Takayuki Ichikawa³, Ankur Jain^{1

4}, Rini Singh³

Affiliations

¹ Center for Renewable Energy and Storage, Suresh Gyan Vihar University, Jaipur 302017, India.
² Department of Physics, JECRC University, Jaipur 303905, India.
³ Graduate School of Advanced Science & Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan.
⁴ Natural Science Centre for Basic Research & Development, Hiroshima University, Higashi-Hiroshima 739-8530, Japan.

Abstract

The superior hydrogen storage properties makes the KSiH₃ system a potential hydrogen storage material for practical applications. A theoretical capacity of 4.3 wt% bring this material to the front line of all the available hydrogen storage materials; however, the activation barrier of the reaction restricts the system to absorb and desorb hydrogen reversibly at elevated temperatures even if the thermodynamics suggest its room temperature operation. Several catalysts have already been tested to enhance its kinetic properties. In this work, the efforts were made to reduce the activation energy by using Zr-based catalysts to the KSi/KSiH₃ system. The value of activation energy was found to be lowest (i.e., 87 kJ mol^-1) for the ZrH₂-added KSiH₃ system. The mechanism of this improvement was investigated by using X-ray photoelectron spectroscopy (XPS).

Keywords: XPS; activation energy; ball milling; catalyst; metal hydride; silanide.

Grants and funding

This research received no external funding.