Researchers at the University of Bath are part of an international team demonstrating a promising new way to convert carbon dioxide (CO₂) into methanol using electricity rather than heat - a development that could significantly reduce the energy costs of recycling carbon into valuable fuels and chemicals.

The research, published in Nature Catalysis, includes key contributions from Dr Matthew Potter, an Early Care Researcher (ECR) Core member of the Institute for Sustainability and Climate Change (ISCC), whose work helps reveal, for the first time, how these reactions unfold at the atomic level while they are actually happening.

Rethinking CO₂ chemistry

As efforts to remove CO₂ from the atmosphere accelerate, a critical question remains: what should be done with captured carbon once it has been removed?

One option is to convert CO₂ into methanol, a versatile platform chemical used to make fuels, plastics and a wide range of everyday products. However, CO₂ is an exceptionally stable molecule, meaning it resists chemical change.

Traditionally, converting CO₂ into methanol requires high temperatures (over 200 °C) and high pressures, along with metal catalysts such as copper and zinc. These harsh conditions consume large amounts of energy and can reduce how selectively methanol is formed.

“There’s a fundamental trade off,” explains Dr Potter. “You need energy to activate CO₂ so it will react but too much heat actually makes methanol less likely to form.”

Electricity instead of heat

The international research team addressed this challenge by taking a fundamentally different approach. They sought to activate CO₂ molecules using electricity rather than thermal energy.

The process combines a newly designed catalyst with a technique known as non thermal plasma catalysis, in which an electrical current energises gas molecules without significantly heating the system overall. This makes it possible to initiate chemical reactions at low temperatures which in turn favour the selective formation of methanol.

The catalyst itself is based on a zeolite, a porous, molecular scale framework widely used in industry, into which copper and zinc atoms are incorporated. These metals are already known to be effective for CO₂ to methanol conversion under conventional conditions, but their behaviour under electrically generated plasma had not previously been understood in detail.

Watching chemistry as it happens

A crucial advance in the study was understanding why this combination works so well. To understand this, researchers wanted to see not just what goes in and what comes out, but to have the ability to observe the chemistry unfold in real time.

Dr Potter led work to investigate the catalyst using operando spectroscopy, an approach that allows researchers to see how materials behave while a chemical reaction is actively taking place.

Using advanced x-ray absorption spectroscopy at the Diamond Light Source, the UK’s national synchrotron facility, the team was able to track how copper and zinc atoms inside the catalyst changed during CO₂ conversion.

“This takes us beyond a ‘black box’ view of chemistry,” says Dr Potter. “Instead of only seeing the final products, we can see which parts of the catalyst are actually responsible for forming methanol, and how they behave under realistic reaction conditions.”

The experiments pushed the limits of what can currently be measured, enabling observations that had not previously been possible for plasma driven catalytic systems.

A proof of concept for low energy carbon recycling

The results show that high methanol selectivity can be achieved without external heating or high pressure, providing a compelling proof of concept for lower energy CO₂ conversion pathways.

While the system is not yet ready for industrial scale up, the combination of electrical activation and real time observation provides a powerful platform for future catalyst and process design.

“This work shows that we don’t have to be constrained by traditional high temperature chemistry,” says Dr Potter. “With new ways of activating molecules, and of directly observing what’s happening, we can start to design fundamentally different and more efficient processes.”

Global collaboration for global challenges

The project formed part of a large international consortium funded through the EU’s Horizon 2020 programme, bringing together teams in the UK, Japan and China with expertise spanning catalyst design, plasma chemistry and advanced characterisation.

For the Institute for Sustainability and Climate Change, the study highlights the value of interdisciplinary and internationally connected research needed to address complex climate challenges and links fundamental science with long term visions for sustainable industrial systems.