Highly dispersed CuyAlOx mixed oxides as superior low-temperature alkali metal and SO2 resistant NH3- SCR catalysts

Journal article

For NO x removal from the exhaust gases of municipal solid waste (MSW) incinerators by selective catalytic reduction (SCR) technology, a suitable SCR catalyst which is active at low temperatures and robust to the presence of alkali metals and SO 2 is highly desired. In this contribution, we report the successful fabrication of a highly dispersed Cu y AlO x (y = 2–4) mixed oxides for NH 3 -SCR catalyst using high surface area, flower-like highly dispersed AMO-Cu-Al-CO 3 LDHs precursors. The influence of the Cu/Al ratio (2, 3, 4, and 5), calcination temperature (400, 500, 600, and 700 °C), and testing temperature (150, 200, 250, and 300 °C) on the activity of the Cu y AlO x mixed oxide catalysts were systematically investigated. Among all samples, Cu 4 AlO x showed the highest NO x conversion of 91.1% at 200 °C. After being thermally treated at 700 °C, the NO x conversion of Cu 4 AlO x was still as high as 84.7%, which is much higher than that of the control catalyst 10 wt% CuO/γ-Al 2 O 3 (57.5%). XRD and HR-TEM analyses suggested that the highly dispersed CuO nanoparticles are the active species for the SCR reaction. The catalytic De-NO x performance of Cu 4 AlO x in the presence of alkali metals (K and Na) and SO 2 was also studied. In the presence of 50 ppm SO 2 , the NO x conversion of Cu 4 AlO x (78.4%) was much higher than that of CuO/γ-Al 2 O 3 (48%). The selectivity of NO x conversion to N 2 and resistance to H 2 O (and co-existence of H 2 O and SO 2 ) for Cu 4 AlO x catalyst were also evaluated. In all, we have demonstrated that the newly obtained Cu 4 AlO x catalyst not only possesses higher thermal stability and higher low temperature (150–250 °C) catalytic activity, but also has much better alkali metal (K and Na), SO 2 , and H 2 O resistance than a conventional CuO/γ-Al 2 O 3 catalyst.

Authors: Yan, Q; Nie, Y; Yang, R; Cui, Y; O'Hare, D

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Elsevier
• Journal: Applied Catalysis A: General More from this journal
• Volume: 538
• Pages: 37-50
• Publication date: 2017-03-18
• Acceptance date: 2017-03-17
• DOI: 10.1016/j.apcata.2017.03.021
• ISSN: 0926-860X
• Keywords: Sulfur dioxide; Alkali metals; Layered double hydroxides; Selective catalytic reduction; Municipal solid waste incineration