Novel Preparation of Cu and Fe Zirconia Supported Catalysts for Selective Catalytic Reduction of NO with NH3

Abstract

Copper and iron promoted ZrO2 catalysts were prepared by one-pot synthesis using urea. The studied catalysts were characterized by XRD, N2 physisorption, XPS, NH3-TPD, and tested in the selective catalytic reduction of NO with NH3 (NH3-SCR) in the absence and presence of water vapor under the experimental conditions representative of exhaust gases from stationary sources. The influence of SO2 on catalytic performance was also investigated. Among the studied catalysts, the Fe-Zr sample showed the most promising results in NH3-SCR, being active and highly selective to N2. The addition of SO2 markedly improved NO and NH3 conversions during NH3-SCR in the presence of H2O. The improvement in acidic surface properties is believed to be the cause.

Investigation of Mn Promotion on HKUST‐1 Metal‐Organic Frameworks for Low‐Temperature Selective Catalytic Reduction of NO with NH3

“…This can be linked with the acidic properties of HKUST‐1‐Mn3.75, which probably has been improved in contact with SO 2 . Similar observation was reported for ZrO 2 supported catalysts modified with copper and iron [4] . On the other hand, ammonia can react with sulfur dioxide leading to accumulation of ammonium sulfate compounds, such as NH 4 HSO 4 (ammonium bisulfate) and (NH 4 ) 2 SO 4 (ammonium sulfate) which block the pores of catalyst [58] .…”

“…Similar observation was reported for ZrO 2 supported catalysts modified with copper and iron. [4] On the other hand, ammonia can react with sulfur dioxide leading to accumulation of ammonium sulfate compounds, such as NH 4 HSO 4 (ammonium bisulfate) and (NH 4 ) 2 SO 4 (ammonium sulfate) which block the pores of catalyst. [58] Clogging of the pores can be directly correlated with deactivation of the NH 3 -SCR catalyst.…”

“…Metal oxides, mixed metal oxides, and zeolites were found very promising in NH 3 ‐SCR. Unfortunately, in most cases, they do not reveal high activity below 250 °C [4,5] . This does not solve the problem of low‐temperature operation demand.…”

“…Unfortunately, in most cases, they do not reveal high activity below 250°C. [4,5] This does not solve the problem of low-temperature operation demand. Lately, metal-organic frameworks (MOFs) attracted much interest mostly due to their multifunctional properties.…”

“…Still, metal-organic frameworks are scarcely reported for NH 3 -SCR, and only several reports may be found in this research area. [11,12,21,[13][14][15][16][17][18][19][20] HKUST-1 is one of the most popular MOFs used for adsorption, air purification, and gas separation of molecules such as NH 3 , [22] H 2 O, [23] CO 2 , [24] CH 4 , or H 2 . [25] HKUST-1 has been reported for the first time in 1999.…”