Hydrothermal aging alleviates hydrocarbon poisoning effects on high-silica Cu-SSZ-16 catalysts for NH3-SCR

作者：Huan Zhou, Jianqi Liu, Yan Zhang, Shichao Han, Jinpeng Du, Wenpo Shan · 发表于：Journal of Environmental Sciences · 年份：2024 · DOI：10.1016/j.jes.2024.12.017 · 被引用次数：6 · 研究领域：Catalytic Processes in Materials Science、Catalysis and Oxidation Reactions、Catalysis and Hydrodesulfurization Studies

Hydrocarbons (HCs) exert toxic effects on the activity of Cu-based zeolite catalysts for NH 3 -SCR on diesel vehicles. This study investigated the hydrocarbon resistance of both fresh and hydrothermally aged high-silica Cu-SSZ-16 catalysts. It was found that low-temperature activity of Cu-SSZ-16 catalyst decreased after C 3 H 6 poisoning, which was mainly due to the blockage of pore channels and the coverage of Cu active sites as well as acid sites by the formation of carbon deposits. Additionally, [Cu(OH)] + -Z was proposed to be more easily affected by C 3 H 6 poisoning than Cu 2+ -2Z. Hydrothermally aged Cu-SSZ-16 presented better C 3 H 6 resistance than the fresh catalyst since less carbon deposits were accumulated and [Cu(OH)] + -Z species were partially transformed to more-stable Cu 2+ -2Z in the aged sample. This was probably because of the reduction of acid sites and the formation of CuO x , which enhanced the oxidation of C 3 H 6 , thereby inhibiting the formation of carbon deposits. In addition, the coverage of the active Cu species also influenced the adsorption and oxidation of NO, causing a decrease in low-temperature activity. Thus, the low-temperature activity could be fully recovered by hydrothermal treatment at 500 °C due to the removal of carbon deposits and recovery of Cu active sites as well as acid sites. In summary, high-silica Cu-SSZ-16, with high resistance to HCs and excellent hydrothermal stability, is a competitive candidate as a catalyst for the NH...