Hypercrosslinked organic polymer based carbonaceous catalytic materials: Sulfonic acid functionality and nano-confinement effect

Porous hypercrosslinked polymers (HCPs) based novel metal-free heterogeneous solid acid catalysts were synthesized via Friedel-Crafts alkylation by self-condensation of bischloromethyl monomers such as α,α'-dichloro-p-xylene and 4,4'-bis(chloromethyl)-1,1'-biphenyl, followed by post-sulfonation process to generate acidic sites. The obtained HCP-based solid acids possessed large amounts of acidic sites homogeneous dispersed over the large surface area of more than 1000m²g^-1, and narrow dispersed pores mostly centered at about 2nm, the junction region of micro and mesopores. Assessed in Friedel-Crafts alkylation and Beckmann rearrangement reactions, the obtained HCP-based porous solid acid catalysts demonstrated superior performance and special nano-confinement effect in the reactions. These were due to their acidic property and unique pore structure, thus providing an efficient metal-free carbonaceous catalyst for eco-friendly "carbocatalysis" process and some clues to prepare multi-functional catalysts from HCP-based materials.