Liquid Metals and Their Role in Decarbonising the Chemical Industry

The global chemical industry faces a monumental challenge: its significant contribution to carbon dioxide emissions. Each year, this sector emits nearly a billion tonnes of CO2, which is more than double the national output of Australia. This staggering figure underscores the urgent need for innovative solutions to mitigate environmental impact. The production of industrial chemicals, such as fertilizers and polyester, is notoriously energy-intensive. Moreover, these materials often come with built-in emissions due to the reliance on fossil fuel feedstocks. As industries worldwide grapple with the climate crisis, three Australian chemists propose an intriguing solution: using liquid metals with ‘atomic intelligence’ to transform the chemical industry’s environmental footprint.

At first glance, the concept of ‘atomic intelligence’ in liquid metals might evoke images of futuristic, self-assembling robots. However, the reality is far more grounded in practical chemistry. The proposed substances are simple metals such as tin, bismuth, mercury, and gallium, or their alloys. These elements have low melting points, making them easier to work with in their liquid state. At the atomic scale, these metals exhibit unique properties that can enhance the production and removal of various substances, including fuels and pharmaceuticals. The potential of liquid metals as powerful catalysts—substances that speed up chemical reactions and control their products—could revolutionize the industry.

Currently, many industrial reactions rely on solid catalysts, which, while effective, lack the dynamic processing capabilities of their liquid counterparts. Liquid metals offer a more versatile approach, enabling more efficient and controlled chemical reactions. One promising application is in the production of hydrogen, an essential energy source that still suffers from high pollution levels. Liquid metals can play a crucial role in preventing the formation of CO2 during hydrogen production from methane. In this process, the leftover carbon could be transformed into long, solid molecules with various potential uses, thereby reducing waste and emissions.

The versatility of liquid metals extends beyond hydrogen production. They can also be instrumental in manufacturing ammonia for fertilizers, a process that currently contributes significantly to greenhouse gas emissions. Furthermore, liquid metals show promise in addressing plastic pollution by breaking down microplastics more efficiently. While the concept of molten metal is not new, it has largely been overlooked in modern chemistry, primarily due to concerns about the toxicity of mercury, which was once the most commonly used liquid metal. However, the increased availability of safer alternatives like gallium has renewed interest in this field.

This renewed interest comes at a critical time, as the climate crisis and environmental concerns become more pressing. Liquid metals like gallium, tin, and bismuth present safer and more affordable options for the industry. Researchers at the University of Sydney are at the forefront of exploring these possibilities. Led by Professor Kourosh Kalantar-Zadeh, head of the school of chemical engineering, the research team is investigating how liquid metals can make industrial chemical reactions greener and more sustainable. Their findings, published in the journal Science, suggest that liquid metals could significantly reduce the energy consumption and emissions associated with chemical production.

Chemical production is responsible for 10 to 15 percent of global greenhouse gas emissions, with chemical plants consuming 10 percent of the world’s total energy. This energy-intensive nature of chemical reactions used in producing various commodities is a major contributor to high emissions. The research team’s approach involves using liquid metals to facilitate these reactions at lower temperatures, thereby minimizing energy consumption. Liquid metals can dissolve other catalytic metals at low temperatures, enabling them to facilitate reactions with less energy. This breakthrough offers a roadmap for a more sustainable future in the chemical industry.

The unique properties of liquid metals, such as their ability to remain in a liquid state at low temperatures and their high conductivity, make them ideal candidates for revolutionizing chemical processes. Their unique atomic structure may also lead to the development of new materials and products. Further research on liquid metals could pave the way for cleaner fuels and more sustainable materials, significantly reducing industrial emissions and contributing to global efforts to combat climate change. The study highlighting the potential of liquid metals in chemical reactions represents a significant step forward in the quest for a greener future.

Implementing this technology on a broader scale could transform the chemical industry, making it more environmentally friendly and sustainable. The research team has already developed techniques using liquid metals to replace traditional, energy-intensive processes. These techniques allow for chemical reactions to occur at lower temperatures, reducing the overall energy required and the associated emissions. This innovative approach could be applied to a range of products, including plastics, fertilizers, fuels, and feedstock, making the production processes more efficient and less harmful to the environment.

The potential applications of liquid metals are vast and varied. For instance, in the production of green hydrogen, liquid metals can facilitate the process more efficiently, reducing the pollution levels associated with traditional methods. Similarly, in synthesizing specific chemicals and decomposing harmful substances like microplastics, liquid metals offer a more effective and sustainable solution. The concept of using liquid metals for chemical reactions is relatively new and largely unexplored, but the early results are promising and indicate a significant potential for transforming the industry.

Professor Kalantar-Zadeh and his team are optimistic about the future of liquid metals in the chemical industry. By tapping into the ‘atomic intelligence’ of metals in liquid form, they believe it is possible to create a more sustainable and environmentally friendly future. Their research has demonstrated that liquid metals can dissolve catalytic metals at low temperatures, creating alloys that promote chemical reactions without the need for high energy inputs. This approach not only reduces energy consumption but also minimizes the formation of harmful byproducts, making the entire process cleaner and more efficient.

The implications of this research extend beyond the chemical industry. The principles and techniques developed by the University of Sydney team could be applied to other sectors, potentially leading to broader environmental benefits. For example, the use of liquid metals in energy production could result in cleaner, more efficient methods for generating electricity. Similarly, in the field of materials science, liquid metals could enable the creation of new, more sustainable materials with a wide range of applications. The possibilities are vast, and further research is needed to fully explore and realize the potential of liquid metals.

In conclusion, the use of liquid metals in the chemical industry represents a promising avenue for reducing industrial emissions and making chemical production more sustainable. The research conducted by the University of Sydney team highlights the potential of these materials to transform the industry, offering a more efficient and environmentally friendly alternative to traditional methods. As the world grapples with the challenges of climate change and environmental degradation, innovative solutions like this are crucial for building a sustainable future. The unique properties of liquid metals, combined with their ability to facilitate chemical reactions at lower temperatures, make them an ideal candidate for revolutionizing the chemical industry and beyond. The journey towards a greener future is complex and multifaceted, but the pioneering work on liquid metals offers a glimpse of what is possible when science and innovation come together to address global challenges.