Copper manganese oxide enhanced nanoarray-based monolithic catalysts for hydrocarbon oxidation

Abstract

Copper manganese oxide (CuMn₂O₄) was introduced into the nanoarray-based monolithic catalysts system for advanced exhaust after-treatment. Through scalable and cost-effective hydrothermal reactions, nanosheet layers of copper manganese oxide were uniformly coated onto the manganese oxide nanoarrays (HM-PCR), which were grown on the cordierite honeycomb monoliths. The core nanoarray support, HM-PCR, a well-defined array architecture for active material deposition, contributed to an increase of open surface area and thus enhanced catalytic oxidation performance. The CuMn₂O₄ coated nanoarray-based catalyst, NA-CuMn₂O₄, shows efficient 90% propane (C₃H₈) conversion at around 400 °C, which is 50 °C and 75 °C lower than CuMn₂O₄ wash-coated catalyst (WC-CuMn₂O₄) and Pd loaded catalyst (WC-Pd), respectively. Compared to monolithic catalysts with a traditional alumina support, the benefit of nanoarray morphology was demonstrated by correlating the variation of surface area to the reactivity. The incorporation of cobalt ions was found to increase the specific surface area and thus enhance C₃H₈ conversion of CuMn₂O₄. The CuMn₂O₄/MnO₂ nanoarray-based monoliths are promising types of emission control devices.