Design, preparation and testing of effective FeOx/SiO2, catalysts in methane to formaldehyde selective oxidation

A preparation method of highly effective methane to formaldehyde selective oxidation (MPO) FeOx/SiO2 catalysts, based on "adsorption-precipitation" on FeII ions under controlled conditions (ADS/PRC), is reported. The performance of ADS/PRC catalysts in the MPO reaction at 650°C has been compared with that of conventional systems prepared by the "incipient wetness" of silica carriers with aqueous solutions of FeIII (INC/WET). The ADS/PRC method, enabling a higher dispersion of the active phase, provides very effective MPO catalysts featuring CH4 turnover frequency (TOF) and HCHO productivity (STYHCHO) values larger than those of the counterpart INC/WET systems.