Non-thermal plasma combined with CuO/sepiolite clay catalyst removal NO

摘要

The modified sepiolite clay catalyst cleaned by nitric acid, impregnated copper nitrate, drying and then calcinations, combined with non-thermal plasma produced by dielectric barrier discharge reactor to remove NO. With XRD analyzed pattern of original and modified sepiolite, the Mg element and others were effectively removed from the original sepiolite by cleaning with nitric acid; the stable phase CuO was formed in the surface of catalyst after immersion and calcinations; the structure of sepiolite almost did not changed after modification so the sepiolite has a good ability to act as catalyst carrier. SEM micrograph of the sepiolite catalyst indicated the number of micro hole were improved and the surface area was increased by treatment, the active point of CuO was uniformly distributed in the surface without stack mess. The results show the acid concentration, cleaning time has an effect on NO removal ratio. Catalyst activity increased and then decreased with increasing of the acid cleaning time. The ratio increased with the increasing of input voltage. The modified sepiolite catalyst has a good ability to adsorb and store NO and take on Barrier Dielectric for Discharge. The order NO removal ratio is as follows: (plasma+ catalyst with acid cleaning, copper nitrate immersed and calcinations) > (catalyst with acid cleaning, copper nitrate immersed and calcinations) > (plasma+ sepiolite catalyst without acid cleaning, but copper nitrate immersed and calcinations) > (plasma+ original sepiolite) > only plasma. When the input voltage was 35kV, the nitric acid concentration of 1.5mol/L used to immerse original sepiolite for 48h, 8% CuO was loaded in the sepiolite surface and the catalyst was calcinated at 500°C for 5h, the maximum ratio value may reach 71%. The This research has been supported by the National Natural Science Foundation of China (No.21076002) investigation proved that the modified sepiolite catalyst combined with non-ther--mal plasma had a good ability to remove NO.