Developing Benign Ni/g-C₃N₄ Catalysts for CO₂ Hydrogenation: Activity and Toxicity Study

Area of Science:

• Catalysis
• Materials Science
• Green Chemistry

Background:

• Developing efficient catalysts for carbon dioxide (CO2) valorization is crucial for sustainable chemistry.
• Non-noble metal catalysts offer a cost-effective alternative to precious metals for CO2 hydrogenation.
• Graphitic carbon nitride (g-C3N4) shows promise as a support material for catalytic applications.

Purpose of the Study:

• To investigate the CO2 hydrogenation performance of Ni and Cu non-noble metal clusters supported on g-C3N4.
• To understand the effect of temperature on CO2 conversion and product selectivity.
• To evaluate the potential of g-C3N4 as a support for atom-economy-designed catalysts.

Main Methods:

• Synthesis and characterization of Ni/g-C3N4 and Cu/g-C3N4 catalysts using techniques like XRD, AFM, ATR, Raman imaging, and TPR.
• Testing catalyst performance in CO2 hydrogenation at 1 bar.
• Assessing catalyst cytotoxicity using the HaCaT cell line.

Main Results:

• Both Ni/CN and Cu/CN catalysts exhibited stable activity and good CO2 conversion.
• Increasing temperature enhanced CO2 conversion and shifted selectivity towards CO (Cu/CN) or methane (Ni/CN).
• Ni/CN catalysts achieved high conversion (>80% CH4 yield at 623 K) with significantly lower Ni loading compared to reference catalysts.
• Low catalyst concentrations showed no cytotoxicity to HaCaT cells.

Conclusions:

• g-C3N4 is a suitable support for developing efficient, atom-economy-designed non-noble metal catalysts for CO2 hydrogenation.
• The developed catalysts offer a promising route for CO2 valorization with reduced environmental and health impacts.
• Further research into catalyst design and process optimization can lead to more sustainable chemical transformations.