Processes comprising: (a) providing a shaped body having a surface and comprising a metal oxide, and impregnating the shaped body with a liquid comprising an unsaturated compound; (b) subjecting the impregnated shaped body to thermolysis under an inert gas atmosphere at a temperature of 250 to 400° C., such that at least 10% by weight of the unsaturated compound is thermalized to form a layer of a high molecular weight polyaromatic on at least a portion of the surface of the shaped body; and (c) reacting the shaped body with a reagent to functionalize the polyaromatic layer, wherein the shaped body has a smallest dimension in any spatial direction of at least 1 mm to provide a shaped catalyst body having ion- exchange properties; shaped catalyst bodies prepared thereby and uses therefor as catalysts.