HIGH-TEMPERATURE CATALYST SUPPORTS AND CERAMICS MEMBRANES - METASTABILITY AND PARTICLE PACKING

Parameters and/or processes responsible for the stability of catalyst supports and ceramic membranes are discussed. Two major parameters/pro cesses were identified which are responsible for the stability of sol- gel defined nanostructured oxides at elevated temperatures. They are m etastable-to-stable phase transformation and structure and packing of primary particles within the aggregate. Based on these observations, s trategies to develop thermostable nanostructured oxides for high-tempe rature membrane and catalyst applications are discussed by taking tita nia and titania-alumina nanocomposites as examples.