EFFECT OF WATER-CONTENT IN THE PRECURSOR SOLUTION ON THE CATALYTIC PROPERTY AND STABILITY OF SR0.8LA0.2MNAL11O19 HIGH-TEMPERATURE COMBUSTION CATALYST

The effect of water content in the precursor solution on thermal stabi lity in the preparation of Sr-hexaaluminate was examined by XRD, SEM, TEM, BET and XPS analysis. Large water content caused a rapid decrease in the surface area of hexaaluminate. XPS analysis also showed enrich ment of the element when large amount of water was added during the hy drolysis step. This result implies that the addition of large amount o f water affected the surface properties of hexaaluminate; the instabil ity of the unbalanced surface composition as compared with bull; compo sition, accelerated the sintering phenomena which resulted in the rapi d particle growth and drastic decrease of surface area. (C) 1998 Elsev ier Science B.V. All rights reserved.