Liquid metals could be a long-awaited solution to “greening” the chemical industry, according to researchers testing a new technique; They hope it could replace energy-intensive chemical engineering processes that date back to the early 20th century. Approximately 10-15% of global greenhouse gas emissions are the result of chemical production. Additionally, chemical plants consume more than 10% of the world’s energy.

Recently published findings Nature Nanotechnology, It offers much-needed innovation that moves away from older, energy-intensive catalysts made of solid materials. The research is led by Professor Kourosh Kalantar-Zadeh, Head of the School of Chemical and Biomolecular Engineering at the University of Sydney, and Dr Junma Tang, a collaborator at the University of Sydney and UNSW.

A catalyst is a substance that allows chemical reactions to occur faster and easier without participating in the reaction. Solid catalysts, usually solid metals or solid metal compounds, are widely used in the chemical industry to make plastics, fertilizers, fuels and raw materials.

However, chemical production using solid processes is energy intensive and requires temperatures up to thousands of degrees Celsius.

Instead, the new process uses liquid metals; In this case, it dissolves tin and nickel, which gives them unique mobility, allowing them to migrate to the surface of liquid metals and react with incoming molecules such as canola oil. This causes canola oil molecules to spin, break apart and recombine into smaller organic chains, including propylene, a high-energy fuel critical to many industries.

“Our method offers the chemical industry unprecedented opportunities to reduce energy consumption and green chemical reactions,” said Professor Kalantar-Zadeh.

“The chemical sector is expected to account for more than 20 percent of emissions by 2050,” Professor Kalantar-Zadeh said. “But chemical manufacturing is much less visible than other sectors; a paradigm shift is vital.”

How does the process work?

Atoms in liquid metals are arranged more randomly and have more freedom of movement than in solids. This allows them to easily come into contact and participate in chemical reactions. “Theoretically they can catalyze chemicals at much lower temperatures, which means they need much less energy,” Professor Kalantar-Zadeh said.

In their study, the authors dissolved high-melting-point nickel and tin in a gallium-based liquid metal with a melting point of only 30 degrees Celsius.

“By dissolving nickel in liquid gallium, we can access liquid nickel, which acts as a ‘super’ catalyst at very low temperatures.” For comparison, the melting point of solid nickel is 1455 degrees Celsius. “The same effect is felt, to a lesser extent, for metallic tin in liquid gallium,” said Dr. Tang.

Metals are dispersed at the atomic level in liquid metal solvents. “So we have access to single-atom catalysts. A single atom is the largest surface area available for catalysis, which offers a tremendous advantage for the chemical industry,” said senior author and DECRA Fellow Dr. Arifur Rahim.

The researchers said their formula could also be used for other chemical reactions by mixing metals using low-temperature processes.

“Catalysis requires such a low temperature that theoretically we could even do it in a kitchen with a gas stove, but don’t try to do it at home,” Dr Tan said.