Selected Pt/WO3-ZrO2 catalysts, promoted by Al, Si and Fe metal ions and isomorphously substituted into the zirconia framework, were studied and compared with their undoped equivalents as catalysts for C-7 isomerization. They were characterized by XRD, UV-vis and TPD-TPR techniques. A mechanism was proposed for the positive dopant effect on the catalyst activity. (C) 2016 Elsevier B.V. All rights reserved.