Development of nano nickel-based sorbent for ultra-deep desulfurization of ultra low sulfur diesel for fuel cell applications

A novel nickel-based sorbent for the reactive adsorption desulfurization of diesel fuel was developed by the incipient wetness impregnation of nickel on mesoporous silica, MCM-48, and evaluated in a fixed-bed flow sorption system at 200 °C using a commercial ultra-low sulfur diesel (ULSD) with sulfur content of 15 ppmw. The prepared sorbent with 20 % nickel loading on MCM-48 showed the excellent sorption performance, as the loaded nickel highly dispersed on the MCM-48 with the average nickel particle size of 2.5 nm. A breakthrough capacity of 2.1 mg-S/g-sorb at a breakthrough sulfur level of 1 ppmw was obtained. The desulfurization reactivity of the alkyl DBTs on the nickel-based sorbents is dependent on not only the number, but also the size of the alkyl substituents at the 4- and 6-positions of DBTs. Among all sulfur compounds, 4,6-DEDBT shows the lowest reactivity, due to the strong steric hindrance of the two ethyl groups.