Surfactant-assisted synthesis of MOF-derived CeO2 for low-temperature catalytic o-xylene combustion

Abstract

CeO2 applied for catalytic elimination of volatile organic compounds have received great attention for their superior oxygen storage capacity and reducibility. In this work, CeO2-C catalyst is prepared through pyrolysis of Ce-MOF precursor with assistance of cetyltrimethylammonium bromide (CTAB). The T50 and T90 of the strip-like CeO2-C are 155 and 193 °C (WHSV= 48000 mL·g−1·h−1, o-xylene concentration= 500 ppm), which take significant advantages over literature results. Compared with the catalyst prepared without CTAB (CeO2-B), the CeO2-C possesses a 1.5 times reaction rate and an apparent activation energy (Ea) as low as 39.82 kJ·mol−1. Meanwhile, CeO2-C also demonstrates good thermal stability in long-term test and water resistance. The characterization results reveal that the assistance of CTAB increases oxygen vacancy density and generates more active oxygen species, resulting in the improvement of catalytic performance. Furthermore, the reaction route, o-xylene → 2-methyl benzaldehyde (benzaldehyde) → benzoic acid → maleic anhydride → ethanol and acetone → H2O and CO2, is also probed.