A team of chemists from Ruhr-Universität Bochum (RUB), a German university, has developed a cheap catalyst for the production of ‘greener’ plastic.

This development could push forward PEF (polyethylene 2,5-furandicarboxylate) plastic as a sustainable alternative to PET (polyethylene terephthalate), the common fossil-fuel based plastic used to make water bottles, soda containers and more.

Additionally, hydrogen is created during the reaction, which can serve as a potential energy source.

The study

The researchers developed a nickel boride catalyst, which is cheaper than most catalysts and readily available.

It effectively works to turn HMF (5-hydroxymethylfurfural), a biorefinery product derived from non-food biomass, into FDCA (2,5-furandicarboxylic acid).

Both HMF and FDCA are “listed as highly interesting candidates on the way to a ‘green’ chemical industry,” said Stefan Barwe, a research fellow at the RUB Center for Electrochemical Sciences and co-author of the study.

“FDCA can be used as commodity chemical for the production of the sustainable polymer PEF, a potential replacement for the heavily produced fossil fuel based PET.”

The ‘green’ status of these chemicals has been known for some time, but efficient oxidation of HMF to FDCA has been a challenge.

The nickel boride catalyst pushed that dilemma to the side.

“FDCA is interesting for the industry because it can be processed into polyesters,” Barwe said in a statement.

“That’s how PEF, an alternative to PET, can be made — all based on renewable raw materials, namely plants.”

A paper describing the full study and presenting the full team is published in the journal Angewandte Chemie.

Hydrogen production

In testing, the catalyst was able to turn 98.5 percent of HMF into FDCA in just 30 minutes without producing any waste.

The researchers were also able to produce hydrogen during the reaction, which could be used as a potential energy source.

Traditionally, hydrogen is gained from water using electrolysis, but that process also creates oxygen, which is energy-consuming reaction step.

When the team linked hydrogen evolution and FDCA production, they were able to bypass oxygen evolution.

What’s next?

At this point, FDCA production from HMF is a developing topic.

“For the electrochemical oxidation of HMF, solutions have to be developed to overcome or circumvent the HMF degradation induced by high alkaline concentrations,” said Barwe.

More work needs to be done before PEF can effectively replace PET.

“The production of HMF has to be scaled, because it is still too expensive at the moment,” said Barwe.

“In order to bring PEF to a point at which it can be a replacement for the heavily used PET, its production has to be cheap.”

Clearly, there is still room for development and improvement, but a more sustainable method for plastic production is on its way.