The present invention relates to a process for preparing a microcomposite comprising a highly fluorinated ion-exchange polymer containing pendant sulfonate functional groups, said polymer existing as aggregated particles entrapped within and dispersed throughout a network of silica. Due to their high surface area and acid functionality, these microcomposites possess wide utility as improved solid acid catalysts, particularly in the substitution of aromatic compounds, in the decomposition of hydroperoxides, and in the isomerization of olefins.