Propane CO₂ (dry) reforming over bimetallic Mo-Ni/Al₂O₃ catalyst

An evaluative investigation of propane CO₂ reforming over bimetallic alumina supported 5%Mo-10%Ni catalyst has been carried out in a fixed-bed reactor at 0.1MPa and temperatures ranging from 823 to 973K. Temperature-programmed calcination revealed the metal nitrate decomposition of Mo-Ni catalyst at around 475K, while TPR analysis showed the complete reduction of fresh catalyst at 973K. Physicochemical properties of Mo-Ni/Al₂O₃ catalyst were determined from N₂-physisorption, H₂-chemisorption, NH₃ and CO₂-temperature-programmed desorption as well as X-ray diffraction analysis. NH₃-TPD analysis revealed that the Mo-Ni/Al₂O₃ catalyst surface was populated with weak and strong Lewis acid sites, while CO₂-TPD showed only one peak assigned to weak Lewis basic site. Increased CO₂ partial pressure in feed caused an initial increase in H₂, CO, and CO₂ reaction rates, peaked at stoichiometric feed ratio (R), CO₂:C₃H₈, of 3 followed by a gentle decrease for R>3. H₂:CO and CH₄:CO experienced logarithmic decay with increased reactant ratio, while CO:CO₂ ratio remained constant at 2. Time-on-stream analysis revealed that Mo-Ni is a stable and active catalyst at different temperatures during propane dry reforming. A global kinetic expression corresponding to carbon deposition was obtained over various feed compositions and temperatures. Post-reaction data from TPR-TPO-TPR-TPO confirmed the presence of at least two carbon pools, C_α and C_Β. The former, atomic carbon is reactive with H₂ and the latter, dehydropolymerised and aged carbonaceous matter, is only removed by O₂.