New Catalyst Has Been Developed That Addresses Turning CO2 and Methane Into Something Valuable and Useful

Wherever harmful greenhouse gas emissions cannot be avoided, they should be turned into something useful: this is known as "carbon capture and utilization," and special catalysts are required for this.

Until recently, the problem has been that a coating of carbon soon accumulates on these catalysts, a process known as "coking," and the catalyst loses its effectiveness.

A novel technique was used at TU Wien: small metallic nanoparticles were created on perovskite crystals using a particular pre-treatment.

The contact of the crystal surface with the nanoparticles guarantees that the correct chemical reaction occurs without the feared coking effect.

Greenhouse gases are converted into synthesis gas

(Photo : Marek Piwnicki/Unsplash)

Carbon dioxide (CO2) and methane are the two most significant man-made greenhouse gases contributing to climate change, as per ScienceDaily.

Both gases are frequently found together, for example, in biogas facilities.

According to Professor Christoph Rameshan of the Institute of Materials Chemistry at TU Wien, "methane dry reforming" is a method that can be used to convert both gases into useful synthesis gas at the same time.

Methane and carbon dioxide are converted into hydrogen and carbon monoxide, from which additional hydrocarbons, including biofuels, may be produced very easily.

The TU Wien team has now developed a catalyst with fundamentally different features.

"We employ perovskites, which are oxygen crystals that can be doped with various metal atoms," explained Christoph Rameshan.

Nickel or cobalt can be inserted into perovskite metals, which have previously been utilized in catalysis.

The nickel or cobalt atoms migrate to the surface and form nanoparticles after a particular pre-treatment of the crystal with hydrogen at roughly 600 °C.

The size of the nanoparticles is critical: success has been obtained with nanoparticles with diameters ranging from 30 to 50 nanometers.

The required chemical reaction subsequently occurs on these small grains, but the oxygen in the perovskite hinders the creation of carbon nanotubes.

The new perovskite catalysts could be used anywhere methane and carbon dioxide are produced at the same time, which is common when dealing with biological substances, such as in biogas plants.

The composition of the resulting synthesis gas can be influenced by the reaction temperature.

As a result, additional processing of climate-damaging greenhouse gases into lucrative goods might become an important component of a sustainable circular economy.

Also Read: Satellite Images Revealed Russia, US Are Major Sources of Methane Leak

How does CO2 become converted into these other products?

According to Thomas Jaramillo, head of the SUNCAT Center for Interface Science and Catalysis, a joint institute of Stanford University and the Department of Energy's SLAC National Accelerator Laboratory, one approach to lower the amount of carbon dioxide in the atmosphere would be to capture the potent greenhouse gas from factory and power plant smokestacks and utilize renewable energy to convert it into products we need.

The level of CO2 in the atmosphere is presently at its highest level in 800,000 years.

It's essentially a sort of artificial photosynthesis, which is why the Joint Center for Artificial Photosynthesis at the Department of Energy finances the research, as per SciTechDaily.

Solar energy is used by plants to transform CO2 from the atmosphere into carbon in their tissues.

Similarly, scientists wanted to create technologies that employ renewable energy, such as solar or wind, to transform CO2 emissions from industry into carbon-based goods.

Nitopi, Jaramillo, SUNCAT staff scientist Christopher Hahn, and postdoctoral researcher Lei Wang explained their study and why it is important.

According to Hahn, one method is known as electrochemical CO2 reduction, in which CO2 gas is bubbled up through the water and interacts with the water on the surface of a copper-based electrode.

Copper functions as a catalyst, bringing the chemical constituents together in such a way that they react.

Simply said, the first reaction removes one oxygen atom from CO2 to produce carbon monoxide, or CO, a valuable industrial chemical in its own right.

Other electrochemical processes then convert CO into useful compounds such as alcohol, fuels, and other substances.

According to Wang, when it comes to boosting a catalyst's performance, one of the most important factors they consider is how to make them more selective, so that they produce only one product and nothing else.

Catalysts are used in almost 90% of fuel and chemical manufacture, and removing undesired byproducts is a significant cost

Scientists also looked at how to make catalysts more efficient by expanding their surface area, so that more reactions may occur concurrently in a given amount of material.

This boosts the rate of production.

They just found something unexpected: increasing the surface area of a copper-based catalyst by shaping it into a flaky "nanoflower" connected layer the process more efficient and selective.