Structure-Induced Iron Carbides for CO₂ Hydrogenation into Liquid Fuels

Area of Science:

• Materials Science
• Catalysis
• Chemical Engineering

Background:

• Coal is an abundant energy source but its use leads to significant greenhouse gas emissions.
• Efficient CO2 utilization is crucial for mitigating climate change and developing sustainable energy solutions.

Purpose of the Study:

• To design an efficient catalyst for CO2 hydrogenation to liquid fuels using coal-based activated carbon.
• To explore the structure-activity relationship of iron-based catalysts supported on tailored carbon materials.

Main Methods:

• A two-step coking-activation strategy was employed to synthesize coal-based activated carbon supports with controlled structures.
• Iron nanoparticles were loaded onto the carbon supports, and the resulting catalysts were characterized using various techniques.
• CO2 hydrogenation reactions were performed to evaluate catalyst performance, with in situ spectroscopy and DFT calculations used for mechanistic studies.

Main Results:

• The developed coal-based activated carbon supports exhibited tunable structures, including scale-like and alveolate morphologies.
• The catalyst FeK@AC-2.0-750, featuring high Fe5C2 content, demonstrated superior performance in CO2 hydrogenation.
• The catalyst achieved 29.3% CO2 conversion and 58.8% C5+ selectivity, outperforming those with commercial carbon supports.

Conclusions:

• The study highlights the potential of coal-derived nanocarbons as supports for efficient CO2 conversion.
• The findings provide insights into designing advanced iron-based catalysts for C1 chemistry and sustainable resource utilization.