Selective oxidation of methane to formaldehyde over doubly copper–iron doped zinc oxide catalysts via a selectivity shift mechanism

Formaldehyde formation from a CH4-air mixture (1 : 1) is induced by a selectivity switch from C2 hydrocarbon products over ZnO to the oxygenated product over doubly Cu–Fe doped ZnO to yield up to 76 g of CH2O (kg cat.)–1 h–1.