Solar catalysis offers tantalizing glimpse of a clean energy future
Imagine if we could use water and solar energy to recycle carbon dioxide into environmentally friendly fuels. This would not only solve the global energy crisis but global warming at the same time. Talk about killing two birds with one stone!
Referring to her planned system for sustainable fuel production as “deliberately ambitious” Scientia Professor Rose Amal’s vision for our global energy future is, in fact, quite audacious.
The Australian Laureate Fellow and her burgeoning research team from the PartCat (Particles and Catalysis) research laboratory, which includes catalysis experts: Dr Yun Hau Ng and Dr Jason Scott, have attracted so much attention from their core research on harnessing solar energy through catalysis, that in 2016 their research papers appeared as the cover stories in no less than six high-impact journals.
These papers describe the group’s through three key areas – thermo-catalysis, photo-catalysis and electro-catalysis; as Professor Amal explains:
“Thermal catalysis has been around for more than two centuries, with the thermal energy usually provided by a high temperature furnace. Our focus is to design a sustainable catalyst system which can be activated at lower temperatures by using the heat of the Sun.”
“In photo-catalysis, on the other hand, we’re using the UV, or the visible part of the solar spectrum, to activate the catalyst for the chemical reaction.”
Catalysis is the heart of chemistry – most, if not all, chemical reactions need catalysts – so we want to make these reactions efficient and the process as sustainable as possible. Turning to the Sun as an energy source is an obvious way to focus our investigations because it could reduce our reliance on unsustainable fossil fuels.
Scientia Professor Rose Amal
“Another catalytic process we’re studying is electro-catalysis. This is where we apply an electric potential to drive the reaction. The electricity can be generated using solar cells so we are still using the Sun’s energy to sustainably activate the catalyst,” she continues.
But how does the PartCat research team envisage using these types of chemical reactions for sustainable energy?
Professor Amal says they are exploring a number of options, but one example would be to use a catalytic reaction to split water. “When you break down a water molecule into hydrogen and oxygen, the hydrogen can be used in fuel cells to generate sustainable electricity,” she says.
In the case of one of their electro-catalysis experiments, they were able to successfully demonstrate the use of carbon as the catalyst. In this experiment, they converted carbon dioxide – a very stable compound – to carbon monoxide, which can be blended with hydrogen to give synthesis gas (Syngas), a precursor for producing hydrocarbon fuels.
“This particular paper was well received because the carbon catalyst is cheap and abundant,” she explains. “Not many people are studying carbon based electro-catalysts for carbon dioxide reduction yet. Most are still utilising expensive catalysts, like platinum, therefore exploring carbon as a catalyst for carbon dioxide reduction is scientifically significant and could have a great impact.”
Professor Amal believes chemical engineers have an important role to play in solving the challenges of the 21st century by finding more sustainable ways to drive chemical reactions. “Catalysis is the heart of chemistry – most, if not all, chemical reactions need catalysts – so we want to make these reactions efficient and the process as sustainable as possible. Turning to the Sun as an energy source is an obvious way to focus our investigations because it could reduce our reliance on unsustainable fossil fuels.”
According to Professor Amal, while there are other research groups in the world who are looking at either thermo-catalysis, photo-catalysis or electro-catalysis in isolation, PartCat are the only group who have the skills and expertise to look at all three of these processes. In some reactions, they are even studying the synergy of two of these different driving forces together, such as photo-thermal and photo-electrical processes. Dr Scott is the leader of the photo-thermal team, while Dr Ng heads the photo-electrochemical group.
“Thousands of papers on new photo-catalyst developments, for example, have been published. However, the research remains fragmented and the improvement in the overall energy conversion efficiency has been marginal,” Professor Amal continues.
“We are looking at an integrated system approach, by understanding the basic science, developing new materials, and engineering the right hybrid systems to deliver practical, real-world applications.”
Professor Amal is very proud of the work they’ve completed so far and highly encouraged by the national and international interest in the research of her team. “If successful, we would have an almost ideal outcome in terms of sustainable energy and clean environment,” she says.
PartCat on the cover
You can read all the cover stories here:
- Catalysis Science Technology
- ACS Catalysis
- Advanced Materials
- Chemistry - A European Journal
- ACS Applied Materials and Interfaces