Ruthenium-based catalyst could be biomass game-changer

Illustration of the Ru/Nb2O5 catalyst. The weak electron-donating capability of ruthenium (Ru) nanoparticles supported on niobium pentoxide (Nb2O5) is thought to promote reductive amination while preventing the formation of undesirable by-products. Image credit: Tokyo Institute of Technology
Illustration of the Ru/Nb2O5 catalyst. The weak electron-donating capability of ruthenium (Ru) nanoparticles supported on niobium pentoxide (Nb2O5) is thought to promote reductive amination while preventing the formation of undesirable by-products. Image credit: Tokyo Institute of Technology

Researchers at Tokyo Institute of Technology have developed a new catalyst to improve the synthesis of primary amines (derivatives of ammonia).

It is claimed that in the future the newly developed ruthenium based catalyst could also impact the development of biofuels and bio-oils.

Primary amines are industrially important compounds which are used in the preparation of a wide range of dyes, detergents and medicines. Many attempts have been made to use platinum, nickel or palladium catalysts to improve the synthesis of amines, but few have been successful in reducing the formation of tertiary amines and other undesired by-products.

In a study published in the Journal of the American Chemical Society, the team from Tokyo describe how they’ve developed a ‘highly selective’ catalyst consisting of ruthenium nanoparticles supported on niobium pentoxide (Ru/Nb2O5). The team have demonstrated that the catalyst is capable of producing primary amines from carbonyl compounds with ammonia (NH3) and dihydrogen (H2), with negligible formation of by-products.

After discovering the ruthenium based catalyst consistently produces yields of over 90% when converting furfural to furfurylamine in a process known as reductive amination1, Michikazu Hara of Tokyo Tech's Laboratory for Materials and Structures and his team explored how effectively the catalyst could break down biomass in the form of glucose into 2,5-bis(aminomethyl)furan, a monomer for aramid production.

Experiments with a nickel based catalyst led to a yield of around 50% from glucose-derived feedstock, while the new catalyst produced a yield of 93% with little to no by-products observed. According to a statement from Tokyo Institute of Technology, this means the Ru/Nb2O5 catalyst represents a major breakthrough in the clean, large scale production of biomass-derived materials.

Illustration of the Ru/Nb2O5 catalyst. The weak electron-donating capability of ruthenium (Ru) nanoparticles supported on niobium pentoxide (Nb2O5) is thought to promote reductive amination while preventing the formation of undesirable by-products. Image credit: Tokyo Institute of Technology