The catalyst is intended to be used with solar technology. The discovery comes from the laboratories at the University of Adelaide functions to drive the process of combining carbon dioxide with hydrogen to produce methane (the main component of the fossil fuel natural gas) and water. This involves capturing carbon from the air so it can be used for industrial processes. Since methane is the basis of natural gas it is therefore an effective industrial fuel.
This builds on research which shows hydrogen can be generated efficiently through the use of solar energy. Instead of following a standard process, if hydrogen is combined with carbon dioxide to produce methane, this ends up being a safer option than simply using hydrogen directly for industrial processes. For this hydrogen-carbon dioxide reaction to happen, an efficient catalyst is needed. A catalyst is a substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change.
The catalyst used for the study was synthesized using porous crystals termed metal-organic frameworks. These crystals allow precise spatial control of the chemical elements. Metal–organic frameworks are compounds consisting of metal ions or clusters coordinated to organic ligands. This was a complex task according to lead researcher Dr Danielle Kennedy: “The catalyst discovery process involved the synthesis and screening of more than one hundred materials.”
Some catalysts were unsuitable because they showed poor carbon dioxide conversion; or they produced dangerous levels of carbon-monoxide production; or due to other factors, such as the temperature at which they operated at. In contrast the new catalyst efficiently produced pure methane from carbon dioxide. For this, only a small quantity of the catalyst was needed to give a high production of methane. The catalyst can also operate at low temperatures and at low pressures, making it good for solar thermal energy processes.
The significance of the research is that it could lead to the full replacement of fossil fuels while also allowing the energy industry to use existing carbon-based fuel technologies, with the effect of no increase to levels of atmospheric carbon dioxide.
The research is published in the Journal of Materials Chemistry, in a research paper titled “Highly active catalyst for CO2 methanation derived from a metal organic framework template.”