Oxidative Desulfurization of Dibenzothiophene Using Catalyst of NiO Impregnated on Magnetic Silica Sand from Parangtritis Beach

Abstract

Oxidative desulfurization of dibenzothiophene (ODS-DBT) using catalyst of NiO impregnated on magnetic silica sand from Parangtritis beach (Ps) had been evaluated. The NiO-Ps catalyst was prepared using wet impregnation method with Ps to Ni (NO3)2·6H2O weight ratio of 1:1. The catalyst was calcined at a temperature of 400 °C for 5 h under flow of 20 mL min-1 of N2 gas. The ODS-DBT process was carried out using NiO-Ps catalyst on solution of n-hexane with a sulfur content of 500 ppm under variations of temperature, time, and H2O2 volume. The results of XRD and FTIR indicated the main minerals of Ps were quartz, alumina, and magnetite. The Ps and NiO-Ps had crystallinities of 59.97 and 70.32% with crystal sizes of 16.32 and 10.95 nm. The SEM-EDX and TEM analysis showed the surface of Ps was flat and NiO-Ps was rough. The BET-nitrogen absorption-desorption indicated the Ps and NiO-Ps were mesoporous materials with average pore diameters of 11.98 and 24.01 nm, total pore volumes of 0.008 and 0.057 cm3 g-1, and specific surface areas of 2.611 and 9.502 m2 g-1. The Ps and NiO-Ps have acidity values of 1.14 and 1.74 mmol g-1. The optimum desulfurization using NiO-Ps catalyst in the ODS-DBT was 79.40% obtained at a temperature, time, and H2O2 volume of 60 °C, 30 min, and 0.42 mL.