Gram-scale ruthenium catalysts templated on halloysite nanotubes and MCM-41/halloysite composite for removal of aromatics from gasoline fraction

Abstract

Gram-scale Ru-containing catalysts templated on structured mesoporous silica of MCM-41 type reinforced with natural aluminosilicate halloysite nanotubes (HNT), as well as their analogues based on pristine halloysite, were synthesized by wetness impregnation under microwave irradiation. The structural properties and elemental composition of the catalysts were studied by TEM, XRD, TPR-H₂, and XRF. Textural characteristics were determined by low-temperature nitrogen adsorption/desorption. The catalytic properties in hydrogenation of aromatic-rich model feed and gasoline fraction were studied in batch reactors in the temperature range of 60–150 °C, under hydrogen pressure of 3 MPa, and a substrate/Ru molar ratio of 2000 for 3 h. Comparing the results of the catalytic tests, we can conclude that each material has its own advantage for the treatment of aromatic-rich feed under specific operating conditions. The Ru/HNT and Ru/MCM-41/HNT catalysts performed best in the 60–100 °C and 60–80 °C temperature regions, respectively, for the removal of aromatics, e.g. benzene, to meet ecological restrictions while retaining the octane numbers.