Synergistic Catalytic Removal of NO x and n‑Butylamine via Spatially Separated Cooperative Sites

• Published in: Environmental science & technology 2024-07, Vol.58 (26), p.11781-11790
• Main Authors: Yan, Lijun, Zhu, Huifang, Liu, Xiangyu, Peng, Dengchao, Zhang, Jin, Cheng, Danhong, Chen, Aling, Zhang, Dengsong
• Format: Article
• Language: English
• Subjects: Catalysis; Nitrogen Oxides - chemistry; Oxidation-Reduction; Physico-Chemical Treatment and Resource Recovery; Volatile Organic Compounds - chemistry
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/acs.est.4c01840

Synergistic control of nitrogen oxides (NO x ) and nitrogen-containing volatile organic compounds (NVOCs) from industrial furnaces is necessary. Generally, the elimination of n-butylamine (n-B), a typical pollutant of NVOCs, requires a catalyst with sufficient redox ability. This process induces the production of nitrogen-containing byproducts (NO, NO2, N2O), leading to lower N2 selectivity of NH3 selective catalytic reduction of NO x (NH3-SCR). Here, synergistic catalytic removal of NO x and n-B via spatially separated cooperative sites was originally demonstrated. Specifically, titania nanotubes supported CuO x –CeO2 (CuCe–TiO2 NTs) catalysts with spatially separated cooperative sites were creatively developed, which showed a broader active temperature window from 180 to 340 °C, with over 90% NO x conversion, 85% n-B conversion, and 90% N2 selectivity. A synergistic effect of the Cu and Ce sites was found. The catalytic oxidation of n-B mainly occurred at the Cu sites inside the tube, which ensured the regular occurrence of the NH3-SCR reaction on the outer Ce sites under the matching temperature window. In addition, the n-B oxidation would produce abundant intermediate NH2*, which could act as an extra reductant to promote NH3-SCR. Meanwhile, NH3-SCR could simultaneously remove the possible NO x byproducts of n-B decomposition. This novel strategy of constructing cooperative sites provides a distinct pathway for promoting the synergistic removal of n-B and NO x .