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

A series of HKUST-1 supported catalysts (also known as Cu-BTC, or MOF-199 [copper(II)-benzene-1,3,5-tricarboxylate]) modified with different loadings of manganese were synthesized and characterized by powder X-ray diffraction, scanning electron microscopy/energy dispersive spectroscopy, nitrogen sorption, thermogravimetric analysis, and temperature-programmed desorption with NH3. The structural and textural properties of the solids, compared to the reference support, are preserved as much as possible when the manganese content is not higher than 5.0 wt.%. This allows to obtain effective catalysts at low temperatures (<200 degrees C) in the selective catalytic reduction of NO with NH3. The highest efficiency is obtained with the catalyst containing 3.75 wt.% of manganese which exhibits NO conversion of 68 % at weight hourly space velocity (WHSV) of 96,000 ml/h g. This performance in NO reduction is recognized to be one of the best in the series of HKUST-1-Mnx catalysts. Nevertheless, their narrow temperature window for the working reaction and sensitivity to the presence of water vapor and sulfur dioxide remain a drawback.

Automated summary

A series of HKUST-1 supported catalysts modified with different loadings of manganese were synthesized and characterized, with the best performance achieved by the catalyst containing 3.75 wt.% of manganese. Despite high efficiency in NO reduction, these catalysts have a narrow temperature window for the working reaction and are sensitive to the presence of water vapor and sulfur dioxide.