Improving the Methane Oxidation by Self-Adaptive Optimization of Liquid-Metal Catalysts

Area of Science:

• Catalysis
• Materials Science
• Green Chemistry

Background:

• Methane (CH4) is a potent greenhouse gas and valuable carbon resource.
• CH4 conversion is challenging due to its stability, often requiring harsh conditions and leading to over-oxidation.
• Traditional catalysts lack structural flexibility for optimizing complex reaction pathways.

Purpose of the Study:

• To develop a novel catalyst with dynamic, self-adaptive structures for efficient methane conversion.
• To investigate the catalytic performance and selectivity of a copper-embedded liquid metal catalyst (Cu-LMC).
• To understand the mechanism behind the enhanced activity and selectivity of Cu-LMC.

Main Methods:

• Synthesis and characterization of a novel Cu-embedded liquid metal catalyst (Cu-LMC) based on gallium alloys.
• Evaluation of catalytic performance for methane to methanol conversion under mild conditions.
• In situ XPS, XAFS analyses, and ab initio Molecular Dynamics (AIMD) simulations to probe catalyst structure and reaction mechanisms.

Main Results:

• Cu-LMC achieved a high methane conversion to methanol yield (5.9 mol·gCu−1·h−1) with 82% selectivity.
• Mild surface oxidation enhanced catalytic activity by forming a beneficial Cu-O-Ga configuration.
• Catalyst's dynamic structure facilitated lower methanol desorption energy and higher by-product formation barriers.

Conclusions:

• Cu-LMC demonstrates superior performance in methane conversion to methanol compared to traditional catalysts.
• Dynamic and self-adaptive catalyst structures are crucial for overcoming limitations in catalytic methane conversion.
• This approach offers a promising strategy for efficient and selective utilization of methane as a chemical feedstock.