Turning CO2 into Methane with Single-Atom Nickel Catalysts

Researchers have developed a method to capture and convert carbon dioxide (CO2) directly into methane (CH4) using advanced nickel (Ni) catalysts. These catalysts, made of single Ni atoms dispersed on electrode surfaces, enable a streamlined process that bypasses energy-intensive CO2 separation steps.

The study explored how CO2 bound in carbamate and bicarbonate forms can be transformed into methane. Results showed single-atom nickel to be uniquely effective for this conversion. Techniques like X-ray photoelectron spectroscopy (XPS) and electron microscopy (EM) confirmed the high activity of these dispersed Ni atoms. Further comparisons with Ni phthalocyanine catalysts supported on carbon nanotubes reinforced their efficiency.

By testing solutions with different capture agents—hydroxide, ammonia, and various amines—the study revealed that carbamate plays a key role in producing methane. Nuclear magnetic resonance (NMR) spectroscopy and control experiments confirmed these findings, showing that carbamate is the main driver of methane production.

Density functional theory (DFT) calculations supported these observations, demonstrating how Ni dispersed on gold surfaces facilitates the direct reduction of carbamate to methane. This innovative approach highlights a promising method for integrating CO2 capture and conversion into useful hydrocarbons, opening new possibilities for sustainable energy solutions.