Nix/TiO2 catalysts for enhancing the selectivity of methylcyclohexane dehydrogenation

Abstract

The dehydrogenation of methylcyclohexane (MCH) is a widely used hydrogen storage technology, but nowadays, precious metal catalysts such Pt are used for this reaction and non-precious metal catalysts suffer from low selectivity and instability problems. Two catalysts, Ni20/TiO2 and Ni20/Al2O3, were prepared through the improved co-precipitation method and their dehydrogenation performance of MCH was compared. It was found that the application of TiO2 carrier could significantly reduce the acidity of the catalysts, and the nickel particles could be stably dispersed on the carriers, which could effectively improve the selectivity of the target product (toluene). In addition, the influences of different Ni contents, reaction temperatures, and weight hourly space velocity (WHSV) on the performance of the catalysts were also evaluated, and the results showed that the catalyst with 17.16% Ni content exhibited high activity with up to 86.48% conversion of MCH and 96.51% selectivity of toluene, under atmospheric pressure condition with the reaction temperature of 375°C and WHSV of 1.9 h−1, while 96.03% and only 42.64%, respectively, for the Ni20/Al2O3 catalyst. In addition, the catalyst exhibited excellent anti-coking ability, indicating that it has a promising future for industrial applications.