Designing, optimization and performance evaluation of the K-Zn0.4Co2.6O4|α-Al2O3|cordierite catalyst for low-temperature N2O decomposition

Abstract

A series of K-Zn0.4Co2.6O4|α-Al2O3|cordierite monolith was developed and optimized with respect to the active phase loading and concentration of potassium promoter. The catalysts were thoroughly characterized by XRD, μRS, XRF, SEM/TEM and their reactivity was evaluated in low-temperature N2O decomposition in 5% N2O and in a model mixture of gases containing typical contaminates for nitric acid plants (1.5% N2O, 1% NOx, 1% H2O, 2.0% O2) in TPSR and isothermal stepwise modes. The optimized catalysts exhibit high performance (X > 90% at T < 400 °C) due to favorable control of the active phase promotion (bulk and surface), morphology (~30 nm grains) and dispersion over the α-Al2O3 micrograins that constitute a compact washcoat.