We have found that Pt/ZrO2/SO4, in the presence of hydrogen, catalyzes the isomerization and cracking of alkanes to give carbenium ions which (a) react with aromatics to yield alkylaromatics as well as alkylated naphthenes and (b) alkylate naphthenic compounds. The products vary with the nature of the aromatic, the length of the paraffinic chain and whether the paraffinic component is added as such or is part of the aromatic ring. For example, little reaction occurs with phenol and a long chain alkane such as dodecane but p-dodecylphenol and anisole react to give alkylated aromatics. The nature of the aromatic can control the distribution of products obtained from added alkanes. Ethylene and even polypropylene alkylate aromatics in the presence of Pt/ZrO2/SO4. The reactions and products obtained are varied and further investigation of the nature of the catalytic action of Pt/ZrO2/SO4 is being pursued.