MXenes, ruthenium support sustainable green hydrogen production

Hydrogen-powered Mustang. (Reference image by John Lloyd, Flickr.)

Researchers at Texas A&M University are using MXenes—a new class of 2D-layered material—as a catalyst to produce green hydrogen in a sustainable manner.

In a paper published in the journal Chem Catalysis, the scientists detail that their MXenes support Ru-atom for hydrogen evolution reaction (HER) catalysis. Currently, platinum is the benchmark catalyst for this reaction.

“My work is centred around designing and evaluating materials to be used as catalysts for sustainable chemical production,” David Kumar Yesudoss, co-author of the study, said. “We have been able to reduce the cost of catalysts that are used in producing green hydrogen by half, which I think is really significant.”

According to Yesudoss and his co-author Abdoulaye Djire, more than 95% of hydrogen used in the chemical industry is produced through steam methane reforming—a fossil fuel method with negative environmental impacts.

“We showed the reaction rate of the electrochemical conversion processes could be increased by modifying the electrochemical responses of these 2D nanostructured materials called MXenes fabricated in our laboratory,” Djire said. “By inserting metal, we were able to tune inexpensive materials and enhance their performance to match closely that of noble metals. Specifically, into the structure of the material, we can enhance the electro-catalytic performance of the material significantly.”

Ultimately, the group aims to further lower the cost of the system by refining the particle size down to individual atoms.

“Such noble metals are hard to mine; our approach will make sure each atom is effectively utilized for green hydrogen production,” Yesudoss said. “Roughly, the size of one atom is less than a nanometer. So, we are talking about 50,000 times smaller than a human hair.”

The group used density functional theory to show synergistic effects between Ru and MXene. This was performed by their collaborator Kingsley Obodo from North-West University in South Africa.

Results showed the ruthenium atoms attach preferably to the surfaces of the MXene. From these findings, a new approach to tuning the electrocatalytic activity of MXenes was found to accelerate the development of cost-effective, efficient and sustainable hydrogen technology.

“If further developed, this technology has the potential to revolutionize the chemical industry,” Djire said.