A new way for deNOx catalyst preparation: Direct incorporation of 12-tungstophosphoric acid H3PW12O40 and platinum into mesoporous molecular sieves material

Direct incorporation of platinum (Pt) and 12-tungstophosphoric acid H3PW12O40 (HPW) into mesoporous MSU-type silica was achieved by using a mixture of cationic and non-ionic surfactants, such as cetyltrimethylammonium (C16TMA+) and Triton (TX-100). Various amounts of Pt (0.3–7 wt%) and HPW (9–49 wt%) were incorporated and the obtained materials were characterized by X-ray diffraction (XRD), chemical and thermal (TG–DTA) analyses, electron microscopies (SEM, TEM), N2 adsorption–desorption measurements, and solid state 31P NMR spectroscopy. The catalytic activity of the calcined silica-based mesoporous molecular sieves containing tungstophosphoric acid (HPW), platinum and platinum–tungstophosphoric acid (Pt/HPW) for NOx reduction with propene was investigated in the presence of oxygen. Samples which contain small amounts of Pt and moderate loadings of HPW were found the most active (up to 97% at 250 °C and for 1 vol.% O2).

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