Dehydrogenation of cyclohexane over Pt/SiO2−AlPO4 catalysts, I. Influence of the catalyst particle size

Abstract

The influence of Pt loading on the metal dispersity and catalytic activity of Pt catalysts on SiO2-AlPO4 in the dehydrogenation of cyclohexane to benzene has been analyzed. Kinetic parameters and apparent reaction rate constants were determined by the Bassett-Habgood equation. Thermodynamic parameters for the reaction were determined.

One‐Pot Synthesis of Benzimidazoles by Simultaneous Photocatalytic and Catalytic Reactions on Pt@TiO2 Nanoparticles

“…This is because the larger sized platinum particles have a lower dehydrogenation activity. As previously reported, [23] the dehydrogenation activity of platinum particles increased with a decrease in their size; in particular, particles with a diameter of < 4 nm showed very high activity. The size of platinum particles on Pt(0.2)@TiO 2 was 2.0 nm, whereas when x = 0.5 and 1.0 the particle sizes were 4.0 and 9.3 nm, respectively.…”

Kinetics of the surface catalyzed reactions: Application of power rate law

“…al. [3], have ignored the volume change, applying equation (4) for cyclohexane dehydrogenation to benzene. Ln(ni/nf) Fig.…”

“…where x is the mole fraction of the product, T the absolute temperature, k' r the apparent rate constant, W the catalyst weight and F the volume flow rate of the reactant through the reaction medium [3]. For a reaction at constant T this would transform to…”

“…A model based on the power rate law developed by Bassett and Habgood [2] is very popular and generally used for the simple kinetic analysis of surface catalyzed reactions [3,4]. The Bassett and Habgood's equation for a first order reaction, with no change in the number of molecules, is expressed in mathematical terms by…”

Characterization of the Structure and Catalytic Activity of Pt/Sepiolite Catalysts

“…Hydrogen chemisorption measurements were made by a dynamic pulse method (16), which had been used by our group in previous work (17,18). The experimental procedure was as follows: Once the TPR profile was recorded, the solid was maintained at the final temperature in an argon stream for 20 min in order to remove residual adsorbed hydrogen, the catalyst was cooled to room temperature, and measurements were made.…”