Polystyrene-Based Hierarchically Macro–Mesoporous Solid Acid: A Robust and Highly Efficient Catalyst for Indirect Hydration of Cyclohexene to Cyclohexanol by a One-Pot Method under Mild Conditions

As a promising synthesis route, indirect hydration of cyclohexene into cyclohexanol by heterogeneous catalysts shows high conversion than that in direct hydration; however, increasing the yield of cyclohexanol from cyclohexene is still a significant challenge. Notably, fabricating a high-performance catalyst is an effective method to improve the yield of the target product. Consequently, a kind of polystyrene-based hierarchically macro–mesoporous solid acid (HP CLPS-SO3H) was successfully prepared by the combination of a colloidal crystal template method with Friedel–Crafts (F–C) cross-linking. Compared with that of other catalysts (3DOM CLPS-SO3H, Amberlyst-15, and HZSM-5) with single-sized pore distributions, HP CLPS-SO3H shows remarkable catalytic performance under mild conditions, in which 90.2% cyclohexanol yield from cyclohexene was obtained. Even after 10 times reuse of the HP solid acid, 80.3% cyclohexanol yield was retained. Moreover, the original morphology was well preserved and the acid sites almost hardly reduced. The as-prepared HP CLPS-SO3H shows promising prospects in the field of cyclohexanol production.