VCU news

By Brian McNeill

Researchers at Virginia Commonwealth University have discovered an effective catalyst for thermochemically converting carbon dioxide into formic acid — a finding that could offer a new strategy for carbon capture, a potentially important tool for reducing CO2 in the atmosphere as the world contends with climate change.

“As we all know, the rapid growth of greenhouse gases in the atmosphere and its adverse effect on the environment is one of the significant challenges that is currently faced by humanity,” said lead author Shiv N. Khanna, Ph.D., chair and Distinguished Commonwealth Professor in the Department of Physics in the College of Humanities and Sciences at VCU. “Catalytic conversion of CO2 into useful chemicals, e.g., formic acid (HCOOH), serves as a cost-efficient alternative strategy for mitigating the adverse effect of CO2. Formic acid is a low-toxic liquid that can be easily transported and stored at room temperature. It can also act as a precursor of high-value-added chemicals, a hydrogen storage vector and a possible future replacement for fossil fuels.”

Khanna and VCU physics researcher Turbasu Sengupta, Ph.D., found that ligated metal chalcogenide clusters can serve as catalysts for the thermochemical CO2 conversion to formic acid. Their findings are described in a paper, “Converting CO2 to Formic Acid by Tuning Quantum States in Metal Chalcogenide Clusters,” published in the Nature Portfolio journal Communications Chemistry.

“We have shown that by using proper combinations of ligands, the reaction barriers of CO2 to formic acid conversion can be drastically reduced, which will significantly accelerate the formic acid production rate,” Khanna said. “So, we will say these reported catalysts have the potential to make formic acid synthesis easier or more feasible. Using a larger-sized cluster with a greater number of sites for ligand attachment or by attaching more potent donor ligands, it is also possible to further increase the formic acid conversion rate compared to what we showed in the computational simulations.”

The research builds on Khanna’s previous research showing that the proper choice of ligands could convert a cluster into a super donor where it can donate electrons or an acceptor where it can receive electrons.

“We now show that the same effect can have significant potential in metal-chalcogenide cluster-based catalysis,” Khanna said. “The possibility of synthesizing stable ligated clusters and controlling their ability to donate or accept electrons offers a new area of catalysis, as most catalytic reactions depend on the donation or acceptance of electrons from the catalysts.”

One of the pioneering experimental scientists in this area, Xavier Roy, Ph.D., associate professor of chemistry at Columbia University, will visit VCU on April 7 for the Department of Physics’ spring colloquium.

“We will work with him to see how we can design and implement a similar catalyst using his experimental laboratory,” Khanna said. “We already had a close collaboration with his group, where we synthesized a novel magnetic material. This time, it will be catalysis.”