Catalysis Today, Vol.307, 20-28, 2018
Synthesis and catalytic performances of K-OMS-2, Fe/K-OMS-2 and Fe-K-OMS-2 in post plasma-catalysis for dilute TCE abatement
Fe-doped manganese oxide octahedral molecular sieves (referred as OMS-2) of cryptomelane type structure were synthesized by co-precipitation and impregnation by refluxing at ambient pressure. The influence of Fe in the MnO2 structure was assessed by several characterization techniques such as ICP-OES (inductively coupled plasma-optic emission spectroscopy), X-ray diffraction, Raman spectroscopy, N-2 adsorption analysis, H-2-TPR (hydrogen temperature programmed reduction), and TGA/DTA (Thermogravimetric analysis/Differential thermal analysis). The co-precipitated sample (Fe-K-OMS-2) shows better performances for TCE removal in moist air when used downstream from a NTP (non thermal plasma) generated in a DC multi-pin-to-plate corona/glow discharge in comparison to the iron free manganese oxide octahedral sieve (K-OMS-2). The enhanced performances towards TCE removal using Fe-K-OMS-2 downstream from the NTP are attributed to high surface oxygen mobility and to an increase of structural defects resulting from improved textural properties. These characteristics allow promoting O-3 decomposition and TCE catalytic total oxidation (CTO) efficiencies.