Hierarchical pore construction of alumina microrod supports for Pt catalysts toward the enhanced performance of n-heptane reforming

Regulation of pore hierarchy has been an important subject in the design of industrial catalysts. Synthesis of alumina without template/additive often results in poor control of morphologies, porosities, and metal dispersion thereafter. Herein, alumina microrods with a tailored pore hierarchy (Rod2) were fabricated without template/additive by tuning the pore structure of the synthetic precursors, which were used as supports of Pt for n-heptane reforming. Improved toluene selectivity was observed at low space velocities as a result of promoted dehydroisomerization of pentacyclic hydrocarbons, presumably due to a combined effect of the desired pore hierarchy and rod morphology. The Pt/Rod2 also showed better resistance to carbon deposition while maintaining good metal dispersion, as compared to alumina supports with spherical morphology or uncontrolled pore hierarchy. The simulation results revealed that the improved toluene selectivity of Pt/Rod2 is attributed to the proper pore combination of meso-pore1 (6–40 nm) and meso-pore 2 (40–300 nm).