One-step hydrothermal synthesis of MnOx-CeO2/reduced graphene oxide composite aerogels for low temperature selective catalytic reduction of NOx

Abstract

In response to the problem of air pollution caused by nitrogen oxides (NOx), we synthesized a three-dimensional (3D) MnOx-CeO2 nanoparticles/reduced graphene aerogel for low-temperature selective catalytic reduction (SCR) of NOx with NH3 by a facile one-step hydrothermal treatment. During the hydrothermal reaction, the graphene nanosheets and MnOx-CeO2 nanoparticles self-assembled into 3D interconnected networks, in which the nanoparticles MnOx-CeO2 with uniform size were densely anchored onto the graphene nanosheets. Besides, the MnOx-CeO2/reduced graphene oxide (RGA) exhibited unique properties such as high specific surface area, and numerous catalytically active sites in comparison with pure MnOx-CeO2 nanoparticles. Evidences have shown that the chemical bonding between MnOx-CeO2 and GO achieved high selective catalytic reduction efficiency. The MnOx-CeO2/RGA composites displayed highly enhanced catalytic activity in comparison to bare MnOx-CeO2 nanoparticles which achieved 99% NOx conversion at 220 °C. This work provided a versatile approach to induce the combination of reduced graphene oxide sheets and other oxide nanoparticles, which opened up new avenues for the design and manufacture of catalysts used for low temperature SCR of NOx with NH3.