Enhanced Degradation Of Carbon Compounds In Waste Gas By Dielectric Barrier Discharge Coupled With Ce/Zr Based Catalyst

The removal of carbon compounds in exhaust gas by dielectric barrier discharge coupled with Ce/Zr-based catalyst technology can be achieved at low background temperature. In this paper,CuCe0.75Zr0.25Oy/X ( X=ZSM-5, Al2O3 and TiO2) catalyst with different support and XCe0.75Zr0.25/TiO2 ( X=Mn,Fe,Co and Ni ) catalyst with different main metals were prepared by impregnation method. The morphological, structural and surface properties of the catalysts were characterized by low-temperature nitrogen adsorption/ desorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS),temperature-programmed reduction by H2 (H2-TPR), temperature programmed desorption by O2 (O2-TPD), temperature programmed desorption by NH3 (NH3-TPD), and Fourier Transform Infrared Spectroscopy (FT-IR). the performance of the catalytic removal of the carbon-containing compounds in exhaust gas was evaluated in a dielectric barrier discharge reactor .The obtained results are as follows:(1) The discharge power of dielectric barrier discharge reactor increased with the input voltage increased. With the power supply frequency increased, the discharge power increased and then decreased, showing significant resonance characteristics. The increase of power produced more energetic particles at the resonant frequency, which was favorable for the degradation of toluene. When the power reached 85 W, the toluene completely decomposed.(2) The removal of CO by CuCeo.75Zro.25Oy/TiO2 and CUZr0.25Oy/TiO2 was carried out by using dielectric barrier discharge. The research showed that the reaction process was carried out in a step-by-step manner: the plasma plays a dominant role in the process of induced reaction, and the combustion process is controlled by thermal catalysis. The addition of Ce in CuCeZr/T improves the reducibility of the catalyst and promoted the oxygen transfer ability. On the one hand, the adsorption of CO on the catalyst surface is facilitated, and on the other hand, the oxidation reaction of CO is promoted.(3) CuCe0.75Zr0.25Oy/X (X=ZSM-5, Al2O3, and TiO2) catalysts were used to remove toluene respectively by combining dielectric barrier discharge. The research showed that the reaction process can be divided into three steps. First, the removal of toluene is affected by dielectric barrier discharge at low discharge power. Second, with the increase of discharge power, the catalyst is activated. Third, the catalyst played the leading role at high discharge power. The results also showed that CuCe0.75Zr0.25Oy/TiO2,which with a large pore size support, contributes to the diffusion of the reactants inside the catalyst. The high degree of dispersion of active species and the presence of lattice oxygen and oxygen vacancies can significantly enhance the selectivity of toluene conversion and CO2. The enhanced acidity of the catalyst causes the formation of coke and impedes the progress of the reaction.(4) The removal of toluene by XCe0.75Zr0.75/TiO2 with different main metals were investigated by dielectric barrier discharge. The results showed that CuCe0.75Zr0.75/TiO2 has the best catalytic effect,NiCeZr/T has a better catalytic effect at lower power,and MnCeZr/T has a higher CO2 selectivity at same toluene conversion. The main reason that CuCeZr/T has high efficiency is below: on the one hand the copper species dispersed on catalyst surface are more than other catalysts. On the other hand, the amount of lattice oxygen of CuCeZr/T is more than other catalysts.