Cobalt-Based Catalyst Supported on Different Morphologies of Alumina for Non-oxidative Propane Dehydrogenation: Effect of Metal Support Interaction and Lewis Acidic Sites

Developing an economically viable and eco-friendly catalyst is essential for the dehydrogenation reaction. In this context, cobalt-based catalysts supported on different morphologies of gamma-Al2O3, nano-sheet (Al2O3-NS), nano-fiber (Al2O3-NF) and nano-plate (Al2O3-NP) were synthesized using wetness impregnation method and tested for non-oxidative propane dehydrogenation reaction. Metal support interaction and Lewis acidic center play a crucial role in propane dehydrogenation reaction; therefore this study focuses on investigating the role of these parameters on the catalytic activity for cobalt-based catalysts. A higher metal support interaction was observed in Co/Al2O3-NS as compared to Co/Al2O3-NF and Co/Al2O3-NP. The presence of tetrahedral coordinated Co+2 in Co/Al2O3-NS leads to higher selectivity towards propylene. The formation of metallic cobalt from Co3O4 precursor present in Co/Al2O3-NP promoted side reactions to form lower hydrocarbons and carbon, which caused catalyst deactivation. In-situ DRIFTS analysis revealed the interaction of propane and propylene gases with the catalyst, which was an important revelation to find the source of carbon deposition.