Abstract
Steam dealkylation (SDA) and hydrodealkylation (HDA) of m-cresol were investigated at 460 °C under atmospheric pressure on potassium-promoted Rh/Al 2O 3 and Ni/Al 2O 3 catalysts. Potassium was used to inhibit acid-like reactions (isomerization and transalkylation ) very easily with cresol. The products were here essentially phenol and gases (H 2, CO, CO 2, CH 4). Kinetic data were similar to those obtained with alkylbenzenes and the reaction mechanism was not basically changed by the presence of the OH substituent. However certain peculiarities were seen: firstly the SDA to HDA activity ratios were higher with cresol than with alkylbenzenes and secondly, phenol was a stronger reaction inhibitor for cresol dealkylation than benzene for alkylbenzene dealkylation. Potassium neutralized the acid sites of the support, increased the stability (less coke) and promoted dealkylation while ring opening was more or less unaffected.
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