Research News: Solid acids offer a simple and more benign alternative to traditional acid-catalyzed chemical processes. Ways in which this opportunity is being addressed through the synthesis and characterization of new solid acids incorporating perfluorosulfonic acid groups as proton donors are described. The Figure represents a perfluorosulfonic acid, which is covalently linked to a porous silica surface at a density of ca. 0.05-0.5 nm(-2).