<p>Direct non-oxidative conversion of abundant methane provides a sustainable route to valuable ethylene and aromatics, avoiding carbon dioxide formation and minimizing intermediate steps, which can improve carbon efficiency. However, due to the high chemical stability of methane, this process is fundamentally constrained by the tradeoff between conversion and selectivity under isothermal conditions. Here we overcome this challenge by using a non-isothermal filament catalyst lightbulb reactor that spatially separates methane activation and selectivity tuning. A joule-heated molybdenum filament reaches 1,000–1,457 °C to activate methane, whereas a palladium (Pd) based catalyst layer coated in the reactor inner shell operates at much lower temperature (154–350 °C) to promote selective hydrocarbon transformation. This decoupling enables high methane conversion in the high-temperature zone, while facilitating controlled aromatization and hydrogenation of reactive intermediates over Pd catalyst in the low-temperature zone, achieving nearly 40% yield of ethylene and benzene, toluene and xylene, with 62% hydrogen yield. Coking—the parasitic buildup of solid carbon deposits on the surfaces within chemical reactors—occurs only on the filament surface, remaining minimal and regenerable. Techno-economic and life cycle analyses indicate strong potential for economically competitive production of value-added chemicals from methane with net-zero emissions using this reactor concept.</p>