Preparation Of Au-Pd/α-MnO₂ Catalysts For The Efficient Removal Of Mixture VOCs

We herein focused on the catalytic removal of volatile organic compounds(VOCs)mixtures over the α-MnO2 nanotubes and their supported Au-Pd alloy nanocatalysts.The interaction between alloy nanoparticles and support significantly improved the lattice oxygen reactivity,and 0.91Au0.48Pd/α-MnO2 performed better than α-MnO2 for the catalytic removal of the individual toluene,m-xylene,ethyl acetate,or acetone under the reaction conditions of VOCs concentration=1000 ppm,VOCs/O2 molar ratio=1/400,and space velocity=40000 mL/(g h).Over the present nanocatalysts,toluene oxidation was greatly inhibited while m-xylene oxidation was uninfluenced in the toluene-m-xylene mixture;acetone or ethyl acetate oxidation suffered a minor impact in the acetone-ethyl acetate mixture;and m-xylene oxidation was enhanced while oxygenated VOCs oxidation was suppressed in the acetone/ethyl acetate-m-xylene mixtures.We deduced that in the oxidation of VOCs mixture,the competitive adsorption on the catalyst surface caused an inhibitory effect,and a rise in the catalyst surface temperature resulted in a promoting effect on VOCs oxidation.Under the adopted reaction conditions,the individual and mixed VOCs could be completely oxidized into CO2 and H2O at a temperature lower than 320℃.The 0.91Au0.48Pd/α-MnO2 nanocatalyst exhibited good water vapor and CO2 tolerance,and high catalytic stability for VOCs mixtures oxidation.Hence,we believed that the manganese oxide supported noble metal alloy nanocatalysts are promising catalysts for the efficient removal of VOCs mixture.