Integrated Carbon Dioxide Capture by Amines and Conversion to Methane on Single-Atom Nickel Catalysts

Area of Science:

• Electrochemistry
• Catalysis
• Carbon capture and utilization

Background:

• Direct electrochemical reduction of CO2 capture species bypasses energy-intensive stripping.
• Atomically dispersed catalysts offer unique reactivity for CO2 conversion.

Purpose of the Study:

• To develop and investigate atomically dispersed nickel catalysts for direct electrochemical conversion of CO2 capture species to methane.
• To elucidate the role of carbamate versus bicarbonate in the conversion process.

Main Methods:

• Electrochemical reduction
• X-ray photoelectron spectroscopy (XPS)
• Electron microscopy (EM)
• Nuclear magnetic resonance (NMR) spectroscopy
• Density functional theory (DFT) calculations

Main Results:

• Atomically dispersed nickel catalysts efficiently convert carbamate species to methane (CH4).
• Carbamate was identified as the primary species responsible for CH4 production, not bicarbonate or dissolved CO2.
• DFT calculations confirmed the activity of single-atom nickel for carbamate reduction.

Conclusions:

• This study presents the first example of direct electrochemical conversion of carbamate to CH4.
• The findings provide new insights into integrated CO2 capture and conversion processes.
• Atomically dispersed nickel catalysts show promise for efficient CO2 valorization to hydrocarbons.