Flexible NiRu Systems for CO₂ Methanation: From Efficient Catalysts to Advanced Dual-Function Materials

Area of Science:

• Catalysis
• Environmental Chemistry
• Materials Science

Background:

• Rising atmospheric carbon dioxide (CO2) levels drive global warming.
• CO2 methanation offers a pathway to convert CO2 into synthetic natural gas (CH4).
• Nickel-Ruthenium (NiRu) based catalysts show potential for efficient CO2 methanation.

Purpose of the Study:

• To design and evaluate a dual-function material (DFM) for integrated CO2 capture and utilization.
• To enhance the CO2 adsorption and methanation performance of NiRu/CeAl catalysts.
• To elucidate the reaction mechanism of CO2 methanation using advanced in-situ techniques.

Main Methods:

• Synthesis and characterization of NiRu/CeAl and NiRu/CeZr catalysts.
• Evaluation of catalytic activity and selectivity for CO2 methanation.
• Modification of NiRu/CeAl with potassium as an adsorbent.
• Time-resolved operando DRIFTS-MS for mechanistic studies.

Main Results:

• NiRu/CeAl catalyst achieved near-equilibrium CO2 conversion with 100% CH4 selectivity at 350 °C.
• The catalyst demonstrated excellent stability under high space velocity.
• Potassium addition created a DFM with enhanced CO2 capture and utilization, producing 0.264 mol CH4/kg.
• Mechanistic studies revealed dual pathways for methane production from CO2 dissociation and adsorption.

Conclusions:

• Advanced dual-function materials can be designed by incorporating adsorbents into effective methanation catalysts.
• The developed DFM is effective for integrated CO2 capture and conversion to CH4.
• Understanding the reaction mechanism is crucial for optimizing catalyst design for CO2 utilization.