Sustainable Electrosynthesis for Rubber Industry Feedstock

Researchers at the National University of Singapore (NUS) have created a sustainable method to produce 1,3-butadiene, a key ingredient used in the manufacture of synthetic rubber, from acetylene. This breakthrough could help lower the energy demands and environmental impact of producing complex molecules, a critical step toward a more sustainable chemical industry.

A promising solution to this challenge is electrification, which involves using renewable electricity to transform simple feedstocks like water and carbon dioxide (CO2) into valuable chemicals and fuels. To make this approach viable, researchers must focus on clear target molecules and efficient production methods. 1,3-butadiene is one such target.

Currently, 1,3-butadiene is mainly produced as a by-product in the cracking process of naphtha or ethane, which is energy-intensive. Despite this, over 18 million tons of this essential compound are produced every year.

A team led by Associate Professor Yeo Boon Siang at NUS has discovered that copper catalysts, when modified with iodide anions, can efficiently convert acetylene into 1,3-butadiene. The results of their research were published in the journal Nature Catalysis. The modified copper catalyst achieved a Faradaic efficiency of 93% at −0.85 V versus the Standard Hydrogen Electrode (SHE), with a partial current density of −75 mA cm-2 at −1.0 V versus SHE. This performance was more than 20 times higher than what previous studies have reported for 1,3-butadiene production.

The research was conducted in collaboration with Dr. Federico CALLE-VALLEJO from the Basque Foundation for Science and the University of the Basque Country in Spain, as well as other experts from institutions like the University of Barcelona and Shell Global Solutions International.

Through detailed analysis of the catalyst using in situ spectroscopy and computational simulations, the team found that iodide helps create stable pairs of copper sites that boost the formation of carbon-carbon (C–C) bonds, which is essential for producing 1,3-butadiene.

Professor Yeo emphasized the collaborative effort between experimental scientists and theorists, as well as the contributions from their industrial partner, in making this sustainable production method a reality. Building on these findings, the team plans to develop new catalysts that can convert acetylene into longer-chain hydrocarbons, which could potentially serve as aviation fuel in the future.