HYDROCONVERSION OF N-HEPTANE ON PLATINUM H-MORDENITE CATALYSTS PREPARED VIA DIFFERENT ROUTES

Two Pt/H-mordenite catalysts were prepared via different routes: (a) by impregnating H2PtCl6 in H-mordenite (HM) (catalyst I) and (b) in NH4HM (catalyst II), followed by drying, calcination and reduction. Catalyst I was found (i) to be more active for n-heptane hydroconversion, (ii) to be more selective for its isomerisation, (iii) to encounter more diffusion limitation as it yields a larger Thiele modulus, (iv) to give a lower effectiveness factor and (v) to give lower activation energy, E(a), values than catalyst II. A study of the pressure effect between 1.5 and 5.5 MNm-2 showed an increase of the catalytic activities to a maximum at 3.0 MNm-2, followed by a decrease. A compensation effect plot gave a linear relationship between In A (pre-exponential factor in the Arrhenius equation) and E(a) at various pressures for n-heptane hydroconversion and its hydrocracking. High selectivities for central hydrocracking of heptane components and high iso-butane to n-butane ratios were obtained on both catalysts.