# Quantum-chemistry calculations of hydrogen adsorption in MOF-5.
> MOF-5における水素吸着の量子化学計算による評価


## Abstract

Molecular hydrogen adsorption in MOF-5 at high loading conditions was investigated using semiempirical PM6 and ab initio MP2 quantum-chemical methods. The PM6 approach estimated a maximum uptake of 3.9 wt% on the inorganic building unit, consistent with experimental estimates of 4.5–5.2%. While PM6 reproduced uptake reasonably well, adsorption energies were overestimated. MP2 calculations with basis set superposition error corrections and full geometry optimization using the 6-31G basis set yielded an adsorption energy of −0.14 kcal mol⁻¹ per hydrogen molecule. Single-point calculations with improved basis sets 6-31G(d,p) and 6-31++G(d,p) produced values of −0.33 and −0.57 kcal mol⁻¹, respectively, the latter approaching the experimental estimate of −1.0 kcal mol⁻¹. The study emphasizes that intermolecular H2–H2 interactions at high loading conditions are critical and were largely neglected in prior computational work conducted at low hydrogen concentrations.

### Mechanism

Quantum-chemical calculations reveal that intermolecular H2–H2 interactions at high loading conditions substantially influence adsorption energetics in MOF-5, a factor underrepresented in prior low-loading computational models.

## Bibliographic

- **Authors**: Gomez DA, Combariza AF, Sastre G
- **Journal**: Phys Chem Chem Phys
- **Year**: 2009 (2009-10-28)
- **PMID**: [19812846](https://pubmed.ncbi.nlm.nih.gov/19812846/)
- **DOI**: [10.1039/b909021e](https://doi.org/10.1039/b909021e)
- **Study type**: other
- **Delivery route**: not specified
- **Effect reported**: not assessed

## Delivery context

The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (empirical LFL of 10%; high-concentration devices are not recommended).

## Safety notes

The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (empirical LFL of 10%; high-concentration devices are not recommended).

See also:
- [Inhalation concentration and LFL / UFL](https://h2-papers.org/en/safety-notes/inhalation-concentration)
- [Consumer Affairs Agency accident cases](https://h2-papers.org/en/safety-notes/accident-cases)

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> **Cite as**: H2 Papers — PMID 19812846. https://h2-papers.org/en/papers/19812846
> **Source**: PubMed PMID [19812846](https://pubmed.ncbi.nlm.nih.gov/19812846/)