The invention relates to a method for the preparation of ethylene from methane comprising contacting a mixture comprising oxygen and methane at a temperature below 900 °C with a catalytic nanowire, wherein the catalytic nanowire is an inorganic nanowire comprising one or more metal elements from any of Groups 1 through 7, lanthanides, actinides or combinations thereof and a dopant comprising a metal element, a semi-metal element, a non-metal element or combinations thereof. The methane is converted by the oxidative coupling of methane (OCM) reaction. The invention relates also to a method for the preparation of a downstream product of ethylene, the method comprising converting methane into ethylene in the presence of a catalytic nanowire and further oligomerizing the ethylene to prepare a downstream product of ethylene, such as gasoline, 1-hexene and/or 1-octene, wherein the catalytic nanowire is an inorganic nanowire comprising one or more metal elements from any of Groups 1 through 7, lanthanides, actinides or combinations thereof and a dopant comprising a metal element, a semi-metal element, a non-metal element or combinations thereof.