New tuneable catalytic membrane reactor for various reactions in aqueous media

Abstract

A catalytic membrane reactor (CMR) was prepared using a commercial ceramic hollow fibre membrane of corundum and Pd-loading was done using incipient wetness impregnation. This single Pd-impregnated catalytic membrane reactor is able to impel different reactions by simply modifying the working parameters. Under very mild conditions, oxidation can be switched to hydrogenation reaction without losing the CMR activity. The catalytic tests were performed in semi-batch mode at room temperature and 60ºC. The reactor was submerged into a vessel containing model solution of phenol or ibuprofen at concentrations in the range of 30–100 ppm. To one end of the membrane reactor hydrogen is supplied, whilst the other end was kept closed. Reactions were done suppling oxygen, air or no gas in the vessel. Depending on the availability of dissolved oxygen, the reactions followed different pathways leading to the hydrogenated or oxidized products. The oxidation pathway goes through the formation of H2O2 that further oxidize the organic matter, while when no oxygen is supply, the hydrogenation of the organic molecules takes place.