Room-Temperature Methane Oxidation to Formaldehyde Mediated by CoMoO⁺ Gas-Phase Cations

Area of Science:

• Catalysis
• Chemical Kinetics
• Materials Science

Background:

• Formaldehyde (HCHO) is a key industrial chemical.
• Direct methane oxidation to formaldehyde is challenging due to C-H bond inertness and overoxidation risks.

Purpose of the Study:

• To explore efficient, room-temperature methane oxidation to formaldehyde.
• To elucidate the mechanism of selective methane conversion using CoMoO+ cations.

Main Methods:

• Gas-phase mass spectrometry experiments.
• Theoretical calculations.
• Investigation of CoMoO+ cation reactivity with methane and oxygen.

Main Results:

• CoMoO+ cations mediate methane to formaldehyde conversion at room temperature.
• A key CoMoOCH2+ intermediate was identified, preventing methanol formation.
• The Mo atom in CoMoO+ activates O2, while both Mo and Co facilitate C-O bond formation.

Conclusions:

• This work presents the first gas-phase conversion of methane to formaldehyde using non-noble metal cations at room temperature.
• The CoMoO+ cation demonstrates high reactivity and selectivity, providing mechanistic insights into methane activation.