Crystallization of ferrierite (FER) on a porous alumina support by a vapor-phase transport method

The formation of a ferrierite (FER) membrane by a vapor-phase transport met hod is discussed. The formation process was studied using X-ray diffraction , scanning electron microscopy (SEM), field emission-SEM and energy dispers ive X-ray analysis. The same location on the top surface was repeatedly obs erved at different crystallization times using SEM. It was found that an al uminosilicate species formed from a dry gel layer was mobile over the surfa ce of support during crystallization. This intermediate aluminosilicate spe cies penetrated into the pores of the alumina support to fill them, generat ing a compact FER-alumina composite layer. (C) 1999 Elsevier Science B.V. A ll rights reserved.