Multidisciplinary determination of the phase distribution for VOX–ZrO2–SO42−–sepiolite catalysts for NH3-SCR

Publication year: 2011
Source: Catalysis Today, In Press, Corrected Proof, Available online 14 June 2011

S.B., Rasmussen , J., Due-Hansen , M., Villarroel , F.J., Gil-Llambias , R., Fehrmann , …

A series of V2O5–ZrO2–SO42−–sepiolite mixtures were extruded, calcined and characterised. NH3-SCR activity was found to be related to the content of the active VOX–ZrO2–SO42− phase (VSZ). The distribution of sepiolite and VSZ at the surface of the mechanical mixtures was studied by the electrophoretic migration technique. The samples were further characterised by nitrogen adsorption, NH3-TPD, XRD and scanning electron micrography techniques. The electrophoretic migration results showed that the addition of sepiolite to VSZ, by kneading in water, had a dramatic effect on the quantity of VOX–ZrO2–SO42− present at the support’s surface, both strongly decreasing the molar fraction of zirconia at…

Graphical abstract

 Graphical abstract:  Highlights: ► Pore size design by variations of clay content. ► Clay shielding of active phase in conformed catalyst. ► Precise prediction of morphology by zero point charge measurements. ► Deviation of apparent activation energy due to induced diffusion limitations.