Sunlight helps convert methane into ethylene in clean new process

A team of researchers has unveiled a solar-powered breakthrough that turns methane, one of the world’s most stubborn greenhouse gases on the planet, into ethylene, a high-value chemical used in plastics, textiles, and solvents.

And instead of relying on the extreme heat typically needed for methane conversion, the process uses nothing more than Australia’s intense sunlight and a new catalyst.

The international project is led by University of Queensland Honorary Professor Lianzhou Wang and co-authored by Dr. Zhiliang Wang from UQ’s School of Chemical Engineering. Their work could pave the way for cleaner chemical production while cutting methane emissions at their source.

Methane has long been considered a serious climate challenge, especially in countries like Australia, where emissions from agriculture and coal mining are significant.

It is over 25 times more potent than carbon dioxide at trapping heat in the atmosphere over a 100-year period. Large emissions from livestock, coal mining, and natural gas operations make it a major contributor to global warming.

Traditional processing methods require temperatures so high that they carry heavy financial and environmental costs.

Dr. Wang said conventional pathways are highly energy-intensive. “Traditional methane processing typically requires extremely high temperatures, which are costly to produce and harmful to the environment,” he said.

Sun-powered chemistry leap

Instead of heat, the team relies on a palladium–gold alloy catalyst paired with titanium dioxide. When exposed to sunlight, this catalyst triggers a reaction that converts methane directly into ethylene.

The innovation lies in re-routing the reaction pathway. “Rather than over-oxidising methane to carbon dioxide, this catalyst adjusts the reaction pathway to favour ethylene formation,” Dr Wang said.

The alloy, he explained, behaves like a synergistic cocktail. “It’s like mixing 2 different catalysts into a cocktail, where the alloy brings out the best properties of both metals.”

The researchers say the process could also address methane emissions at their source. “In Australia, methane emissions from agriculture and coal mining is a problem more serious than carbon dioxide emissions,” he said.

Turning waste into value

By using sunlight as the energy input, the process could offer an affordable, scalable approach that repurposes harmful emissions into economically valuable chemicals.

“But our research shows we can turn a problem into an opportunity by using our intense sunlight to produce a valuable product,” Dr Wang said.

The team envisions future deployment near methane-rich sites, including livestock facilities. “For industrial applications, a photocatalyst bed could be paved on rooftops where methane emissions occur,” Dr Wang said.

One practical limitation today is cost. Palladium and gold are expensive metals. But the researchers are already exploring alternatives. “Our current catalyst contains expensive metals like gold but we’re exploring cheaper alternatives such as iron, which is also widely available,” he said.

Their long-term goal is broader adoption. “Our goal is to make the process efficient and affordable so it can be widely adopted,” Dr Wang said.

The findings were published in the Journal of the American Chemical Society.