Catalytic wet peroxide oxidation of m-cresol over novel Fe2O3 loaded microfibrous entrapped CNT composite catalyst in a fixed-bed reactor

BACKGROUND A novel iron-loaded microfibrous entrapped carbon-nanotube catalyst (Fe 2 O 3 -MF-CNT) was synthesized by wet lay-up papermaking, sintering and metal organic chemical vapor deposition (MOCVD) processes. The catalysts were characterized by N 2 adsorption–desorption isotherm, mercury porosimetry, scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS) and NH 3 temperature program desorption (NH 3 -TPD), and the catalytic performance was tested by catalytic wet peroxide oxidation (CWPO) of m-cresol in a fixed-bed reactor. Finally, the probable multistep reaction pathway for CWPO degradation of m-cresol over Fe 2 O 3 -MF-CNT catalyst in a fixed-bed reactor is presented. RESULTS Characterization results conclude that the prepared catalysts are acid catalysts containing macropores and mesopores. Active components Fe 2 O 3 are evenly loaded on the support by the MOCVD method. CWPO results show that higher temperature and higher space time promote the catalyst performance. Meanwhile, the Fe 2 O 3 -MF-CNT catalyst shows perfect reusability with nearly no iron leaching concentration and high m-cresol conversion (above 95.0%) after four successive runs (24 h). Two possible pathways during degradation of m-cresol are presented. The hydroxyl radicals turn m-cresols into aromatic by-products such as p-toluquinone, 4-methylpyrocatechol and methylhydroquinone, followed by evolution to organic acids, and finally to carbon dioxide and water. During the reaction, more m-cresols are degraded through the pathway in which m-cresols are first converted into 4-methylpyrocatechol. CONCLUSION The novel Fe 2 O 3 -MF-CNT catalyst presented herein owns the advantages of both CNTs and stainless steel fibers, and it shows promising performance in CWPO of m-cresol. © 2018 Society of Chemical Industry