Catalytic applications of composite aerogels

Unitary and composite aerogels with high specific surface areas and pronounced mesoporosity have been prepared by the controlled sol–gel method and subsequent carbon dioxide supercritical drying and heat treatment. The aerogels were characterized by N2 adsorption–desorption, thermal analyses (TGA–DTA), X-ray diffraction (XRD), temperature-programmed desorption (TPD), temperature-programmed reduction (TPR), infrared spectroscopy (IR), transmission electron microscopy (TEM), and reaction tests. The composite aerogels containing extremely small active metal particles showed strong metal-support or metal–metal interactions. The specific catalytic behaviors of aerogel catalysts are explained in terms of their unique textural and chemical properties.