Hydrogen production via CO2-CH4 reforming over cobalt-supported mesoporous alumina: A kinetic evaluation

Abstract

The performance of cobalt supported on mesoporous alumina (MA) under the influence of reaction temperature (923 K-1073 K) and reactant partial pressure (10 kPa-40 kPa) for CO2-CH4 reforming was executed by using a tubular fixed-bed reactor. 10%Co/MA exhibited great catalytic performance (X-CH4 = 70.9%, X-CO2 = 71.7% and D-a = 1.3%), credited to the well dispersion of Co within pore MA, strong metal-support interaction, and MA confinement ability. Based on Langmuir-Hinshelwood kinetic analysis, the dissociative adsorption of both reactants on a single Co active site was selected for this study. The lower value of activation energy (28.9 kJ mol(-1)) suggested that Co particles were finely scattered on the MA surface. Regardless of carbon types, the amount of coke accumulated on the spent 10% Co/MA within 8 h of CO2-CH4 reforming was inhibited due to fine Co distribution inside MA structure, as well as lessened with the raise of reforming temperature from 923 to 1073 K due to improvement in reverse Boudouard reaction.