Transforming methane (CH₄)—the primary component of natural gas and shale gas—into liquid energy carriers like methanol (CH₃OH) under mild conditions has long been a "holy grail" in chemical engineering. However, the extreme strength of the methane C–H bond (439 kJ/mol) requires high activation energy, while the resulting product, methanol, is far more reactive than methane itself, frequently leading to unwanted over-oxidation into carbon dioxide (CO₂).
To overcome this fundamental thermodynamic and kinetic trade-off, a research team led by Prof. Yulian He at Shanghai Jiao Tong University has developed an innovative CO-assisted Pt/CeO₂ – aqueous Cu tandem catalytic system for the direct, selective oxidation of methane to methanol in an aqueous medium. The breakthrough study was published in the journal ENGINEERING Energy .
By decoupling oxygen activation from product preservation using a dual surface and solution-phase engineering strategy, the new tandem catalytic system achieves an impressive CH₃OH yield rate of 14.38 mmol/(g cat ·h) with 100% liquid-phase selectivity toward methanol among detected carbon-containing liquid products under mild batch conditions (180 °C, 1 h).
Key Findings & Scientific Highlights
How the Dual-Regulated Tandem System Works
In traditional methane oxidation, attempting to boost reaction speed usually leads to complete combustion into CO₂. The Shanghai Jiao Tong University team addressed this by assigning complementary roles to solid and liquid components within a unified tandem system:
In situ spectroscopic monitoring (DRIFTS) confirmed that surface methoxy (CH₃O*) is the pivotal reactive intermediate, which rapidly converts into liquid CH₃OH once CO and H₂O are introduced into the atmosphere.
Future Outlook & Industrial Impact
"Selective C–H bond activation under mild conditions remains a monumental challenge," said Prof. Yulian He, corresponding author of the paper. "Our work demonstrates that integrating CO-assisted oxygen activation with solution-phase redox regulation provides a promising conceptual framework for designing scalable, high-selectivity oxidation processes."
While current batch experiments require a significant inventory of CO co-reactant, future research will focus on tuning gas partial pressures (CO/O₂ ratios), improving CO recycling, and optimizing copper-mediated kinetics to enhance overall carbon-utilization efficiency for potential modular, on-site shale gas conversion applications.
Article Information & Links
ENGINEERING Energy
News article
CO-assisted tandem system for the direct conversion of methane to methanol
29-Oct-2026