Insight into the role of metal support interface on shape dependent MnO2 support through the synergistic effect between Ag and MnO2 for the total oxidation of propane

MnO2–based catalysts have been widely used in the removal of short–chain volatile organic compounds (VOCs), such as propane. In this study pre–synthesized shape and size selective silver nanoparticles (AgNPs) decorated on shape dependent MnO2 nanorods (MnO2NR) and nanosphere (MnO2NS) supports to investigate the effect of MnO2 morphology on the complete oxidation of propane. The introduction of well–defined AgNPs on MnO2 is greatly enabled strong metal support interactions (SMSI), reducibility, creation of oxygen vacancies and higher propane adsorption binding energy (by DFT calculation). Various analysis including HRTEM–STEM, XPS, P–XRD, FT–IR, Raman, BET, O2–TPD, H2–TPR and in–situ DRIFT–IR has been carried out in an effort to establish the mechanistic pathway, and it could be concluded that the 1Ag/MnO2NS has substantiated impressive catalytic activity. Further, DFT calculations supported the propane adsorption is more favorable over Ag/MnO2 than bare MnO2 support. The propane oxidation performance over Ag/MnO2NS system is remarkably higher than bare MnO2NR support, probably due to SMSI effect, crystal defects, increased reducibility and oxygen vacancies. Overall, it was concluded that over 1Ag/MnO2NS has displayed excellent catalytic activity via Mars–van–Krevelen mechanism.