Abstract
Low temperature propane oxidation has been achieved by Co3O4-based nano-array catalysts featuring low catalytic materials loading. The Ni doping into the Co3O4 lattice has led to enhanced reaction kinetics at low temperature by promoting the surface lattice oxygen activity. In situ DRIFTS investigation in tandem with isotopic oxygen exchange reveals that the propane oxidation proceeds via Mars-van Krevelen mechanism where surface lattice oxygen acts as the active site whereas O2 in the reaction feed does not directly participate in CO2 formation. The Ni doping promotes the formation of less stable carbonates on the surface to facilitate the CO2 desorption. The thermal stability of Ni doped Co3O4 decreases with increased Ni concentration while catalytic activity increases. A balance between enhanced activity and compromised thermal stability shall be considered in the Ni doped Co3O4 nano-array catalysts for low temperature hydrocarbon oxidation. This study provides useful and timely guidance for rational catalyst design toward low temperature catalytic oxidation.
