Synthesis of Zeolitic Mo-Doped Vanadotungstates and Their Catalytic Activity for Low-Temperature NH3-SCR

Mo was successfully introduced into a vanadotungstate (VT-1), which is a crystalline microporous zeolitic transition-metal oxide based on cubane clusters [W4O16](8-) and VO2+ linkers (MoxW4-x. x: number of Mo in VT-1 unit cell determined by inductively coupled plasma-atomic emission spectroscopy (ICP-AES)). It was confirmed that W in the cubane units was substituted by Mo. The resulting materials showed higher microporosity compared with VT-1. The surface area and the micropore volume increased to 296 m(2).g(-1) and 0.097 cm(3).g(-1), respectively, for Mo0.6W3.4 compared with the those values for VT-1 (249 m(2).g(-1) and 0.078 cm(3).g(-1), respectively). The introduction of Mo changed the acid properties including the acid amount (VT-1: 1.06 mmol g(-1), Mo0.6W3.4: 2.18 mmol.g(-1)) and its strength because of the changes of the chemical bonding in the framework structure. MoxW4-x showed substantial catalytic activity for the selective catalytic reduction of NO with NH3 (NH3-selective catalytic reduction (SCR)) at a temperature as low as 150 degrees C.

Automated summary

Mo was successfully introduced into the vanadotungstate framework, resulting in materials with higher microporosity and stronger acidity, showing substantial catalytic activity for the selective catalytic reduction of NO with NH3.