Zirconia catalysts (ZrO2 and Na-ZrO2) for the conversion of phenethyl phenyl ether (PPE) in supercritical water

Abstract

In this study, the mesoporous ZrO2 and Na-ZrO2 were examined as heterogeneous solid catalysts under supercritical water for the β-ether bond scission of phenethyl phenyl ether (PPE). Na-ZrO2 was more efficient than ZrO2 in the dissociation of PPE. Yields of phenol and styrene were 39% and 16%, respectively, under 97% PPE conversion when 2.5wt.% of Na-ZrO2 catalyst was applied to a batch reactor filled with supercritical water (400°C, 20bar H2 (initial pressure)) containing 2.5wt.% PPE. The characterization revealed that the activities of ZrO2 and Na-ZrO2 were closely associated with the textural and acid/base properties of the catalysts. Notably, the reaction pathway and product distribution were determined by the concentration of acid and base sites on the catalyst's surface.