Abstract
Abstract Selective oxidation of methane to hydrocarbon oxygenates using H2O2 as oxidant over Fe-silicalite-1 catalysts was conducted in a micro fixed-bed reactor. The influence of different crystal sizes, different calcination temperatures and different acidities of the catalysts on the reaction was investigated. A sub-micrometer crystal size around 400 nm was preferable because diffusion limitations occur also in the secondary particle having a size of 200 μm when primary particle size is below 400 nm. After calcination, framework Fe species were found partially migrated to extra-framework positions. By increasing calcination temperatures, a growing fraction of extra-framework Fe species and concurrently a growing variety of types and structures of such species was observed. These newly formed extra-framework Fe species seem to be just responsible for the decomposition of H2O2 and over-oxidation of the oxygenates. Similarly, Bronsted acid sites also seem only to enhance the decomposition of H2O2 and over-oxidation of oxygenates. The formation of Fe sites responsible for selective methane oxidation were already completed upon removal of the template at a calcination temperature of 370 °C.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call