Efficient MnCeOx catalyst derived from MnCe-MOF for chlorobenzene oxidation: Effects of metal ratio, pyrolysis atmosphere and pyrolysis temperature

In this study, a series of binary metal oxide composite materials, MnCeOx, derived from metal-organic framework (MOFs), were successfully synthesized and employed in the catalytic oxidation of chlorobenzene. The metal ratio, pyrolysis atmosphere, pyrolysis temperature, and stepwise pyrolysis have significant effects on the structure and catalytic activity of the materials. The catalytic activity evaluations demonstrated that MnCeOx with a Mn/Ce ratio of 4:1, obtained by pyrolysis at 400 °C first in an argon atmosphere and then in air, exhibited the best catalytic activity (T90 = 196 °C). This notable activity is attributed to its larger specific surface area, mesoporous structure, smaller nanoparticle size, better low-temperature reducibility, and improved oxygen activation ability. The presence of inorganic chlorine on its surface was identified as the primary factor leading to the decline in catalytic activity. By increasing the reaction temperature, the deactivation could be suppressed for more than 90 h.