Low temperature CO catalytic oxidation and kinetic performances of KOH–Hopcalite in the presence of CO2

Abstract

Catalytic removal of CO from fire smoke is critical to ensure human safety and post-fire atmospheric recovery in typical confined spaces. Copper manganese oxide compounds show promise as highly efficient catalysts for low temperature CO oxidation. However, the CO oxidation activity will be affected when the catalyst is applied in fire smoke containing high-concentration CO₂. In this work, a bi-functional catalyst of KOH–Hopcalite is synthesized by impregnation of KOH on Hopcalite (copper manganese oxides mixture) precursor. The catalyst is characterized by N₂ adsorption–desorption, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR). CO oxidation activity and long-term working stability of the precursor and catalyst in the presence of CO₂ are investigated. CO oxidation activity of the precursor would decrease when CO₂ is present. KOH modification can mitigate the inhibiting effect of CO₂ on CO oxidation activity of the precursor. Reaction mechanisms and kinetic performances of the catalyst in the presence of CO₂ are also demonstrated. The catalyst could be potentially utilized as a scavenging agent for post-fire cleanup and atmospheric recovery in confined spaces.