Activity, stability and characterization of NO oxidation catalyst Co/KxTi2O5

Co/KxTi2O5 catalyst with well-dispersed nano-Co3O4 particles, synthesized by an ion exchange method from K2Ti2O5 precursor, showed extremely high NO oxidation activity and good stability. Morphological changes and microcosmic processes during the course of catalyst preparation were examined using atomic absorption spectrometry (AAS), X-ray diffraction (XRD), and scanning electron microscopy-energy dispersive X-ray (SEM-EDX). During the ion exchange of K2Ti2O5 with Co precursor solution, K+ ions were replaced by H+ (H3O+). After calcination at 500 °C, a partially collapsed structure was obtained when the exchange was controlled to a certain degree. Fortunately, the Co that precipitated on this collapsed structure formed highly stable nano-particles of Co3O4. Catalytic activity for the NO oxidation was found to be highly dependent on the loading and particle size of Co and K remaining in the KxTi2O5 support.