Aluminium Hydrogenation

The article illustrated here shows that particles of aluminium metal can help add hydrogen gas to simple organic molecules, a key step in making many industrial chemicals. Normally, this job is done by rare metals like platinum or palladium, and aluminium is considered too reluctant to react with hydrogen in this way. The team made highly porous, nano‑sized aluminium powder and confirmed with several microscopy and surface techniques that it has a metallic core covered by a very thin, uneven layer of oxide, giving it a very large reactive surface.
​
They then tested this aluminium powder in sealed reactors with hydrogen gas and a range of molecules containing C-C double or triple bonds. Under high pressure and elevated temperature, the aluminium could hydrogenate many types of alkenes and alkynes, even some that are normally considered difficult, and it could very slowly saturate benzene, which is usually a demanding target. The process showed unusual patterns in which molecules reacted faster, and the catalyst could be reused, pointing to reactions happening on the metal surface rather than through dissolved aluminium compounds.
​
To understand what is happening at the atomic level, the authors combined experiments with computer simulations of aluminium surfaces. The calculations showed that hydrogen molecules can split and attach to aluminium at stepped surface sites, and that common molecules like ethylene and benzene can adsorb there and be stepwise converted to their hydrogenated forms with reasonable energy barriers. Together, the work suggests that plain aluminium metal, in a finely divided high‑surface form, can participate directly in hydrogen‑based chemistry that has long been associated almost exclusively with transition metals