NOx Removal over Modified Carbon Molecular Sieve Catalysts Using a Combined Adsorption-Discharge Plasma Catalytic Process

Abstract

Carbon molecular sieves (CMS), 13X zeolite, and γ-Al₂O₃ were selected as catalyst support to investigate the NOx adsorption capacity, and a series of Cu modified CMS-based catalysts were used to investigate the NOx adsorption and discharge plasma catalytic removal capacity. Results showed that CMS has a larger NOx adsorption amount and lower desorption temperature in NOx temperature programmed desorption (TPD) process. The addition of Cu benefits the NOx adsorption and nonthermal plasmas (NTP) removal capacity, and the NOx removal capacity and the ratio of NTP/(NTP + TPD) achieved 96.2% and 68.39% over 15%Cu-CMS in 30 min. Water vapor has an obvious effect on the NOx adsorption and discharge plasma catalytic process. In cyclic operation, 15%Cu-CMS has a better NOx adsorption-discharge property. The Brunauer–Emmett–Teller (BET) method showed the average pore width, surface area, and pore volume of the sample after cyclic operation has no significant change. X-ray photoelectron spectroscopy (XPS) showed a new lattice oxygen peak appeared in O 1s spectra, and the Cu₂O peak disappeared in Cu 2p spectra after cyclic operation