Mesoporous zirconium hydroxide, Zr-TMS (zirconium hydroxide with mesostructured framework; TMS, transition metal oxide mesoporous molecular sieves) catalyst has been prepared through the sol-gel method and functionalized with benzyl sulphonic acid (BSA) using post-synthesis route without destroying the mesoporous structure. The benzyl group anchored Zr-TMS (B-Zr-TMS/dropZr-OCH2-Phi) was achieved by etherification reaction of Zr-TMS with benzyl alcohol at 80 degreesC using cyclohexane as solvent. Further, B-Zr-TMS was subjected to sulphonation reaction with chlorosulphonic acid (CISO3H) at 70 degreesC using chloroform as solvent to yield BSA-Zr-TMS (dropZr-O-CH2-Phi-SO3H). Maximum sulphonic acid (-SO3H) loading was optimized with respect to time of functionalization and concentration of CISO3H. Functionalization was carried out by loading the maximum amount of benzyl group over Zr-TMS and varying the concentration Of -SO3H. The synthesized materials have been characterized by powder XRD, FT-IR, elemental analysis, N-2 adsorption-desorption and TPD of ammonia. The catalytic activity of the synthesized catalyst has been performed in liquid phase benzoylation of diphenyl ether to 4-phenoxybenzophenone (4-PBP) using benzoyl chloride as benzoylating agent at 160 degreesC under atmospheric pressure. The same reaction was carried out by sulphated zirconia (SO4 (2-)/ZrO2) and found very poor activity. (C) 2004 Elsevier B.V. All rights reserved.