Chemistry

New Type of Vanadium Can Now be Used for Hydrogenation Instead of Precious Metals

vanadium

Chemist Max Delferro from the U.S. Department of Energy’s Argonne National Laboratory has recently developed a type of vanadium that can be used in hydrogenation reactions. Vanadium is a common metal and therefore inexpensive. With this breakthrough, the unusually active form of vanadium could be used instead of various precious metals currently found in catalysts. Hydrogenation reactions are often used to process petrochemicals.

The scientist converted the common metal into a catalyst useful in a wide range of reactions. This role has up to now been reserved for expensive precious metals.

Hydrogenation is a reaction that is used to make a wide range of products, including petrochemical products, vegetable oils and vitamins. In the new study, Delferro analyzed and boosted the unique catalytic activity of vanadium. Delferro noted that catalyzing these reactions typically requires precious metals, such as palladium, platinum, or rhodium.

Chemists refer to vanadium as a first row transition metal, referring to its place on the periodic table. Like its neighbors, chromium and titanium, vanadium is more abundant and much cheaper than the precious metals.

Vanadium on its own will however not work in the hydrogenation process. To change this, the vanadium has to be in a specific configuration that meets three criteria.

  1. The vanadium has to be in its 3+ oxidation state. This state is very reactive, but also unstable.
  2. The vanadium has to be dispersed on the surface. Any clumps of vanadium atoms that are too big will cease to be as active.
  3. The vanadium atoms have to be “low-coordinated”. This means that there must be electronic room where the target molecules can bind.

Delferro noted that it was very difficult to get single-atom vanadium into this special configuration on a metal oxide surface. Special synthetic techniques such as atomic layer deposition and surface organometallic chemistry are needed. If however vanadium, or any other abundant metal, can be made as catalytically active as the noble metals are, this will result in huge cost savings in the commercially important, yet very common catalytic processes.

Delferro and his team noticed a spectacular boost in catalytic activity once they had managed to create the vanadium in this specific configuration.

The study results were published in an article titled “Isolated, Well-Defined Organovanadium(III) on Silica: Single-Site Catalyst for Hydrogenation of Alkenes and Alkynes,” that appeared online in Chemical Communications on May 9 in the special issue, “ChemComm‘s 2017 Emerging Investigators.”