Methane combustion contributes 30% to global warming, making its conversion to cleaner chemicals a critical challenge. Here, we report a catalyst-free ambient conversion of methane to methanol with a remarkable yield exceeding 650 millimoles per hour and a high conversion rate of ~35%, achieved using in situ–generated water dimer radical cations, ( H 2 O ) 2 + · , in a specially designed batch reactor operating under mild conditions. In a single run, the reactor was typically operated for 10 minutes. The atom efficiency for hydrogen in our approach for methanol synthesis is ~67%. Hydrogen gas is the by-product, produced at a rate of over 2 millimoles per hour. Compared to the previously reported catalytic methods, our production yields are up by between 10 ² and 10 ⁶ times depending on the literature method. This breakthrough enables clean, energy-efficient methane conversion without unwanted oxidation by-products, offering substantial environmental and economic benefits beyond combustion.

The composition and ratio of unsaturated fatty acids in vegetable oils play a crucial role in determining their overall quality. In this study, we present a corona discharge ionization mass spectrometry (MS) method for the rapid differentiation of vegetable oil varieties and their geographical origins under environmental conditions. Abundant water dimer radical cations, (H₂O)₂^+•, were generated by the ionization setup, which effectively activated carbon‑carbon double bonds (C=C) to form epoxidized products. These epoxidation products were analyzed using tandem MS, generating diagnostic fragment ions that precisely identified CC bond positions. Statistical analysis models were subsequently developed using the resulting MS fingerprint data, revealing significant differences between various vegetable oils and olive oils from different origins. Key advantages of this method include minimal sample preparation, rapid analysis, and easily interpretable spectra. This study provides a new MS-based strategy for food quality assessment and offers a promising tool for identifying CC positional isomers in complex systems.