Alkali metal pyridinolate/piperidinolate pairs: A new type of materials for efficient reversible hydrogen storage

Published

April 1, 2025

Author(s)

Alexis Munyentwali, Yang Yu, Xingchi Zhou, Wei Zhou, Qijun Pei, Khai Chen Tan, Anan Wu, Hui Wu, Teng He, Ping Chen

Abstract

Chemical hydrogen storage in organic materials is a promising method thanks to its high storage density, reversibility, and safety. However, the dehydrogenation process of organic materials requires high temperatures due to their unfavorable thermodynamic properties. This study proposes a strategy to design a new type of hydrogen storage materials, i.e., alkali metal pyridinolate/piperidinolate pairs, by combining the effects of a heteroatom and an alkali metal in one molecule to achieve suitable dehydrogenation thermodynamics along with high hydrogen storage capacities. These air-stable compounds can be synthesized using low-cost reactants and water as a green solvent. Thermodynamic predictions indicate that enthalpy changes of dehydrogenation (ΔHd) can be significantly reduced to the optimal range for efficient hydrogen release, exemplified by lithium 2-piperidinolate with a 5.6 wt% hydrogen capacity and a suitable ΔHd of 32.2 kJ/mol-H2. Experimental results obtained using sodium systems validate the computational predictions, demonstrating reversible hydrogen storage even below 100 °C. The superior hydrogen desorption performance of alkali metal piperidinolates could be attributed to their suitable ΔHd induced by the combined effect of ring nitrogen and metal substitution on their structures. This study not only reports new low-cost hydrogen storage materials but also provides a rational design strategy for developing metalorganic compounds possessing high hydrogen capacities and suitable thermodynamics for efficient hydrogen storage.

Citation

Journal of Energy Chemistry

Volume

103

Pub Type

Journals

Download Paper

https://doi.org/10.1016/j.jechem.2024.12.001

Local Download

Keywords

Hydrogen storage, alkali metal pyridinolates, ring nitrogen, metal substitution.

Citation

Munyentwali, A. , Yu, Y. , Zhou, X. , Zhou, W. , Pei, Q. , Chen Tan, K. , Wu, A. , Wu, H. , He, T. and Chen, P. (2025), Alkali metal pyridinolate/piperidinolate pairs: A new type of materials for efficient reversible hydrogen storage, Journal of Energy Chemistry, [online], https://doi.org/10.1016/j.jechem.2024.12.001, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=958700 (Accessed July 8, 2025)