Investigation on removal of multi-component volatile organic compounds in a two-stage plasma catalytic oxidation system - Comparison of X (X=Cu, Fe, Ce and La) doped MnO catalysts.

MnO-X catalysts (X = Cu, Fe, Ce and La) were prepared based on γ-AlO for the mixture degradation of muti-component volatile organic compounds (VOCs) composed of toluene, acetone, and ethyl acetate. The catalysts were characterized, and the density functional theory (DFT) simulation of ozone adsorption on MnO-X were carried out to investigate the influence of adsorption energy on catalytic performance. The results showed that the removal efficiency (RE) of each VOC component was similarly improved by MnO-X catalysts, and the greatest increase in VOCs' removal efficiency was obtained (7.8% for toluene, 86.2% for acetone, and 82.5% for ethyl acetate) at a special input energy (SIE) of 700 J L with MnO-La catalyst. Characterization results demonstrated that MnO-La catalyst had the highest content of low valence Mn elements and the greatest O/O ratio, as well as the lowest reduction temperature. MnO-La catalyst also presented superior catalytic effect in improving carbon balance (CB) and CO selectivity ( [Formula: see text] ). The CB and [Formula: see text] were increased by 47.7% and 12.61% respectively with MnO-La at a SIE of 400 J L compared with that when only γ-AlO was applied. The DFT simulation results of ozone adsorption on MnO-X catalysts indicated that the adsorption energy of catalyst crystal was related to the catalytic performance of the catalyst. The MnO-La/γ-AlO catalyst, which had the highest absolute value of adsorption energy, presented the best performance in improving VOCs' RE.