Environmentally benign multiphase solid–liquid–gas catalysis†
It is significant for the environment that molecular oxygen replaces conventional heavy metal-containing or toxic oxidants to participate in oxidation reactions. However, the involved gas–oil–solid multiphase catalytic reactions usually show low reaction efficiency due to the low solubility of gas in oil. Herein, an organic–inorganic hybrid with certain interfacial activity was synthesized by using an alkoxysilane covalent modified POM. Such a hybrid POM has surface activity and can be adsorbed at the gas–liquid interface, and allows direct contact between the gas, oil and catalyst at the interface. The performance of the foam system is superior to that of the conventional multiphase catalytic reaction at room temperature. In addition, no solvent was required for the reaction. The catalyst can be recovered by centrifugation after the reaction.