Methane was oxidatively coupled to ethylene with an ethylene yield up to 85 percent and a total C-2 hydrocarbon yield up to 88 percent in a gas recycle high-temperature (800 degrees C) electrocatalytic or catalytic reactor where the recycled gas passes continuously through a molecular sieve trap in the recycle loop. Oxygen is supplied either electrocatalytically by means of the solid electrolyte support of the silver-based catalyst or in the gas phase. The C-2 products are obtained by subsequent heating of th e molecular sieve trap. The selectivity to ethylene is up to 88 percent for methane conversion up to 97 percent.