Jointly published by React.Kinet.Catal.Lett. Kluwer Academic Publishers, Dordrecht Vol. 72, No. 1, 125-131 and Akadémiai Kiadó, Budapest (2001) 0133-1736/2001/US$ 12.00. © Akadémiai Kiadó, Budapest. All rights reserved. RKCL3739 COOPERATIVE EFFECT OF PLATINUM AND ALUMINA ON CATALYST DEACTIVATION FOR DEHYDROGENATION REACTION *Sunee Srihiranpullop, Piyasan Praserthdam and Tharathon Mongkhonsi Petrochemical Engineering Research Laboratory, Department of Chemical Engineering, Chulalongkorn University, Bangkok 10330 Thailand Received June 5, 2000 In revised form November 2, 2000 Accepted December 7, 2000 Abstract The cooperative effect on catalyst deactivation of Pt-based catalysts for dehydrogenation reaction was investigated using the combination of Pt- based/SiO 2 and Al 2 O 3 . The presence of the effect was confirmed by reaction test, CO adsorption, H 2 -TPD and TPO. Considering conversion, active site, H 2 uptake and the nature and amount of coke, interestingly, the physical mixture of Pt-based catalyst supported on SiO 2 with 100-120 mesh and Al 2 O 3 60-80 mesh was similar to Pt-based Al 2 O 3 . The concept of combination of two catalytic functions, acidity and metallic species, will certainly provide the possibility of better catalyst design. Keywords: Platinum, alumina, catalyst deactivation, physical mixture INTRODUCTION Carbonaceous deposits cause deactivation of naphtha reforming catalysts which decrease their activity, selectivity and lifetime [1-3]. The catalysts which contain Pt or Pt and a second metal supported on an acidic carrier such as Al 2 O 3 are widely used in the catalytic reforming [4,5]. Coke formation occurs on metals and on acids by different mechanisms, thus, it is essential to understand ______________________________ *Corresponding author E-mail: sunee11@hotmail.com