Promotion effect of lanthanum addition on the catalytic activity of zirconia supported platinum and tungstophosphoric acid catalyst for n-pentane isomerization

Zirconia supported platinum and tungstophosphoric acid (TPA) metal-acid bifunctional catalysts modified with lanthanum were prepared and tested in the reaction involving the production of branched-chain alkanes by skeletal isomerization of n-pentane. The prepared samples were characterized by XRD, FT-IR, H2-TPR and XPS. The catalytic performance was evaluated at 200 °C under atmospheric pressure. According to the conversion and selectivity a promotion effect of La on the activity of Pt-TPA/ZrO2 was found and the optimal doping amount of La depended strongly on the Pt loadings. Simultaneously, cerium was also found to have the similar effect that was weaker than that of La.