Hierarchical Petal-on-Petal MnO2/Vertical Graphene Foam for Postplasma Catalytic Decomposition of Toluene with High Efficiency and Ultralow Pressure Drop

Abstract

A hierarchical petal-on-petal MnO2/vertical graphene (VG) foam catalyst for high-performance toluene decomposition with low pressure drop in postplasma catalysis is demonstrated in this work. The as-fabricated hierarchical structure exhibits high toluene decomposition of ∼93% and ozone conversion of nearly 100% at a high flow rate of 500 mL min–1, significantly higher than those of MnO2 deposited on conventional activated carbon and reduced graphene oxide powders with pressure drop of 2–3 orders of magnitude higher than that of VG foam. The three-dimensional macroporous structure of VG foam is beneficial for gas permeability and thus significantly decreases the pressure drop. The nonagglomerated morphology, large surface area, and sharp exposed edges of VG foam could provide abundant sites for anchoring catalysts without obvious agglomeration. Besides, the unique petal-like structure and open channels of MnO2 prominently enlarge the accessible surface area exposed to gas, leading to enhanced decomposition efficiency.