Morphology control of manganese-based catalysts for low-temperature selective catalytic reduction of NOx

The low-temperature selective catalytic reduction (SCR) of NOx by ammonia is an efficient purification technique to eliminate NOx from stationary combustion sources. In this paper, the different exposed crystal facets of α-MnO2 catalyst were controllably synthesized by using of capping agents of PVP, P123, HAc and CTAB. It was found that all α-MnO2 catalyst prepared using various capping agents are with the same nanorods morphology but different exposed crystal facets. The structure-activity relationship of the catalyst was investigated and the exposed crystal facets showed strong effects of on its activity of SCR for deNOx. The α-MnO2 catalyst with exposed (2 0 0) facets has the highest surface acidity, strongest NH3 and NO adsorption and therefore the best low-temperature SCR activity, with 98% NO conversion at 160 °C.