Catalyst-free activation of CH4 and air into platform chemicals and H2 using parametrized nanosecond pulsed plasma

•Plasma-enabled direct conversion of CH4 and air into H2 and oxygenates was achieved.•Product distribution could be selectively tailored by regulating the pulsed parameters.•The highest H2 selectivity of 46.3 % was obtained at 60 mL/min and 47.1 W.•Lower energy injection and higher flux were beneficial to liquid production (76.8%).