Mordenite zeolites, with controllable crystal morphologies grown orientedly along the c-axis, that is, the running direction of the 12-membered ring main channels, were hydrothermally synthesized. Corresponding Ti-containing mordenite (Ti-MOR) catalysts were then prepared by a secondary isomorphous substation technique, which combined together acid-assisted dealumination and sequential TiCl4 vapor treatment. The diffusion properties of this obtained Ti-MOR catalysts with various morphologies were measured using n-butane as a probe molecule, and their catalytic properties were investigated in the liquid-phase oxidation reactions including ketone ammoximation and aromatics hydroxylation. The mordenite zeolites with smaller crystals, especially consisting of nanoparticles, were in favor of forming tetrahedrally coordinated Ti in TiCl4 vapor treatment. The physicochemical properties and catalytic activity of Ti-MOR exhibited regular changes with an increasing crystal length along the c-axis. The aromatic hydroxylation was more sensitive than ketone ammoximation to the variety of crystal length. In particular, the adsorption capacity (Q(infinity)), apparent diffusivity (D/L-2), turnover number of ammoximation at 2.5 h and hydroxylation at 7 h decreased from 0.78 mmol g(-1), 22.7 x 10(-3) s(-1), 1783 mol (Ti-mol)(-1) and 70.5 mol (Ti-mol)(-1) to 0.59 mmol g(-1), 4.2 x 10(-3) s(-1), 500 mol (Ti-mol)(-1) and 3.4 mol (Ti-mol)(-1), respectively, when the crystal size of Ti-MOR was enlarged from 110 to 5160 nm. The adsorption properties and oxidation activity of Ti-MOR were found to exhibit a distinct change around a crystal length demarcation of ca. 1 mu m. Further studies indicated that the oxidation activity of Ti-MOR was proportional to its apparent diffusivity. (C) 2015 Elsevier Inc. All rights reserved.