New iron catalyst promises green future for hydrogenation

Hydrogenation, the reaction of molecular hydrogen with another compound or element, is one of the world's most highly studied chemical reactions, with industrial applications ranging from petrochemistry, to food production, to pharmaceuticals.

Most such applications of hydrogenation use rare metal catalysts such as palladium or platinum to speed up chemical reactions. While highly efficient, these metals are expensive and limited in supply, posing environmental and economic challenges.

To get around these problems, researchers at McGill University, the RIKEN Center for Sustainable Resource Science and the Institute for Molecular Science developed their new technique using iron, a much less expensive and far more abundant element. Iron has been ruled out in the past due to the fact that it rusts in the presence of oxygen and water, negating its catalytic effect.

The new technique, described in a paper published in the journal Green Chemistry, produces iron nanoparticles directly inside a polymer matrix, which protects the iron surface from rusting while allowing the reactants to reach it and react. The resulting system of polymer-stabilized iron nanoparticles in water is the first of its kind: a safe, cheap and environmentally friendly catalyst system for hydrogenation reactions.

"Our aim is to develop iron-based catalysts not only for hydrogenation but also a variety of organic transformations that can be used in future industrial applications," explains RIKEN researcher Dr. Yoichi M. A. Yamada, one of the authors of the paper. "If rare metal-based catalysts can be replaced by iron-based ones, then we can overcome our costly and dangerous dependency on rare metals."