Room-temperature catalyst-free methane chlorination

The chlorination of methane presents a route for the upgrading of natural gas to value-added products. However, due to the low reactivity of methane, existing chlorination processes require the use of elevated temperatures and catalysts. Here, we report a simple process for the chlorination of methane at near-ambient temperatures using minimal reagents and no catalysts or external sources of energy. The reaction is carried out in an aqueous medium with trichloroisocyanuric acid as a chlorinating agent. The dissolution of trichloroisocyanuric acid in water leads to the sustained and buffered release of hypochlorous acid, which triggers the chlorination of methane by a free-radical mechanism. The process is also general to other alkanes, as shown by a similar chlorination of ethane. Further developments are required for this process to be deployed as a practical method of chloromethane production.