Argonne chemist Max Delferro has developed an unusually active form of vanadium for hydrogenation reactions. Vanadium an inexpensive common metal that could replace some of the precious metals currently.
Researchers at the US Department of Energy’s Argonne National Laboratory have developed an unusually active form of vanadium for hydrogenation reactions. Vanadium is an inexpensive common metal that could replace some of the precious metals currently found in catalysts used in these reactions, frequently used in processing of fuels (petro- and drop-in bio-) and petrochemicals.
The vanadium catalyst exhibits unprecedented reactivity in liquid- and gas- phase alkene/alkyne hydrogenation. Catalyst poisoning experiments revealed that 100% of the V sites are active for hydrogenation. A paper on their work is published in the RSC journal Chemical Communications.
Earth-abundant and inexpensive late first-row transition metals such as Fe, Co, Ni and Cu have been extensively researched as alternative catalysts to noble metals (Ru, Rh, Pd and Pt) for the hydrogenation of unsaturated organic functional groups. While early- and mid-first row transition metals (e.g. Sc, Ti, V, Cr, Mn) have been largely studied for their role as promoter ions for hydrogenation-active metals, much less is known about how the manipulation of their coordination environment and electronic structures can impart hydrogenation reactivity. Some of the rare examples of early transition metal hydrogenation catalysts include (1) in situ reduced titanocenes and (2) a high-valent bis(imido)vanadium(V) catalyst, which operates via heterolytic hydrogenation mechanism.
Vanadium is a first-row transition metal; like its neighbors titanium and chromium, vanadium is much more abundant and cheaper than the precious metals. Unfortunately, most vanadium on its own will not work for the hydrogenation process. To make the vanadium work required a three-step process.
First, the vanadium has to be in its 3+ oxidation state, a very reactive but unstable state. Second, the vanadium had to be relatively dispersed on the surface—if the clumps of vanadium atoms were too big, they would cease to be as active. Last, the vanadium atoms had to be “low-coordinated”, which means that there would be electronic room for the target molecules to bind.