Several vanadyl pyrophosphates ((VO) 2 P 2 O 7 ) with a different microcrystallite structure have been synthesized by a unique process involving the intercalation, exfoliation, and reduction of VOPO 4 .2H 2 O. Stepwise thermal treatment of a suspension of VOPO 4 .2H 2 O crystallites in 2-butanol caused the subsequent processes (intercalation, exfoliation, and reduction) to form VOHPO 4 .0.5H 2 O phases. The resulting VOHPO 4 .0.5H 2 O phases were approximately 1-2 μm in lengths and roughly 0.1 μm in thickness with leaf-like shapes. The catalyst derived from the present novel processes was found to be more active and selective (78% selectivity at about 60% conversion at 663 K) than well-known rose-like crystallites (~1 μm) by the ''organic solvent method'' using iso-butanol and benzyl alcohol. The higher activity of the novel catalyst is attributed to the high surface area (approximately 30 m 2 g - 1 after the reaction for 200 h), and the higher selectivity is probably attributable to the pure phase of (VO) 2 P 2 O 7 because of the smaller dimensions of the crystallites and the preferential exposure of the basal plane of (VO) 2 P 2 O 7 due to the leaf shape.