Effect of oxidised mesoporous carbon containing silver nanoparticle on selectivity of adsorption desulphurisation

Abstract

This paper presents the experimental investigation of the effects of nitric acid oxidation and silver loaded modification of coal tar pitch based mesoporous carbons (MCs) on adsorption capacity of dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT). The structural and textural properties of the samples were characterised by means of X-ray diffraction, scanning electron microscopy, Boehm titration and nitrogen adsorption–desorption techniques. The results show that after oxidative modification, the average pore sizes of MCs were not changed. It is also found that the specific surface area decreased, while the mesopore ratio, the density of the surface oxygen containing groups increased remarkably. Furthermore, silver loaded modification improved the mesopore ratio obviously. The oxidative modification considerably enhanced the adsorption capacity and silver loaded modification improved the selectivity against benzene. After three regeneration cycles, the regenerated adsorption afforded 96 and 93% of the initial adsorption capacities of DBT and 4,6-DMDBT respectively. The results suggest excellent reuse ability of the MCs.