React. Kinet. Catal. Left., Vol. )1, No. 2, 429-43) (1986) CHARACTERIZATIONOF TITANIA AND ZIRCONIA SUPPORTED MOLYBDENUM OXIOE CATALYSTS 8Y LOW TEMPERATURE OXYGEN CHEMISORPTION B. Mahipal Reddy and V.S. Subrahmanyam Catalysis Section, Regional Research Laboratory, Hyderabad 500 007, India Received July 11, 1985 Accepted September 9, 1985 Low temperature oxygen chemisorption (LTOC) has been applied to characterize a series of TiO 2 and ZrO 2 supported Mo-oxide catalysts. The monolayer coverag~ of th~ surfacc~ Js completed when the Mo loading reaches 6% and 4% on the TiO2 and ZrO 2 supports, respectively. The results are explained with the help of a "Pa~ch" model of the Mo-oxide phase. HH3KOTeMnepaTypHa~ XeMOCOp6UHH KHcnopo~a Hcn0~b30Ba~acb ~ xapaKTePHCTHKH cepH~ MO-OKMCHMX KaTanH3aTOpOB Ha T• Zr02 HOCHTen~x.MoH0Cn0~HOe n0KpNTHe nOBepXHOCTH sasepma- eTC~ Korea co~epxaHHe Mo Ha Ts H ZrO 2 HOCHTen~x ~OCTHFa- eT 6% M 4%, COOTBeTCTBeHHO. Pe3ynbTaTM 06~CH~mT Ha OCHOBe Mo~enH "Patch" M0-OKMCHO~ ~a3M. INTRODUCTION Supported molybdenum oxide catalysts are used in many reaction sys- tems, such as hydrodesuifurization, coai iiquefaction, hydrogenation, poiy- merization, partiai oxidation and disproportionation of oiefins. The most efficient utiiization of any supported cataiyst depends on the dispersity of the active component on the surface of the support. This dispersity is often controned, among other factors, by the extent of Ioading and the nature of the support. Aithough much research activity has been devoted towards understanding_ surface structure of Mo-oxide phase on aiumina support [i-)] , similar studies on other supports like titania and zirconia are scarce. Pursuant to our eariier iow temperature oxygen chemisorption studies on Mo/AI20 ) catalysts [4,5], an investigation has been made with the Mo/TiO 2 and Mo/ZrO2 systems by this technique in order to gain some information on the surface structure of the Mo-oxide phase and its dispersity on the two Akaddmiai Kiad5, Budapest