Combinatorial Search for Optimal Hydrogen-Storage Nanomaterials Based on Polymers

TL;DR

This study uses computational methods to identify optimal metal-decorated polymer nanomaterials for hydrogen storage, considering thermodynamic factors and zero-point vibrations, leading to the discovery of a promising Ti-decorated polymer.

Contribution

It introduces a comprehensive combinatorial search approach incorporating thermodynamic effects to find efficient hydrogen storage nanomaterials.

Findings

Ti-decorated cis-polyacetylene achieves 7.6 wt% hydrogen capacity

The material has a volumetric density of 63 kg/m^3 near ambient conditions

Proposes 'thermodynamically usable hydrogen capacity' as a new comparison criterion

Abstract

We perform an extensive combinatorial search for optimal nanostructured hydrogen storage materials among various metal-decorated polymers using first-principles density-functional calculations. We take into account the zero-point vibration as well as the pressure- and temperature-dependent adsorption-desorption probability of hydrogen molecules. An optimal material we identify is Ti-decorated cis-polyacetylene with reversibly usable gravimetric and volumetric density of 7.6 weight percent and 63 kg/m^3 respectively near ambient conditions. We also propose ``thermodynamically usable hydrogen capacity" as a criterion for comparing different storage materials.