Simultaneous catalytic hydrolysis of low concentration of carbonyl sulfide and carbon disulfide by impregnated microwave activated carbon at low temperatures

Abstract

The blank microwave coal-based activated carbons (MCAC) and blank microwave coconut shell activated carbons (MCSAC) were tested for simultaneous catalytic hydrolysis of carbonyl sulfide (COS) and carbon disulfide (CS2) at relatively low temperature (at 50°C). MCAC and MCSAC loaded by Fe–Cu–Ni metal mixed oxides were prepared by sol–gel method, and also tested for the simultaneous catalytic hydrolysis process. The results showed that Fe–Cu–Ni/MCSAC catalyst had the superior activity for the simultaneous catalytic hydrolysis of COS and CS2. These modified catalysts were characterized by XRD, BET, EDS and XPS, the results of which can help us to understand the reasons of the superior catalytic activity and the reasons of catalyst deactivation. Lower generation of sulfate (K3Na(SO4)2), high specific surface areas and more pore sizes of 0.3–1.2nm and 3.5–4.0nm may be the important role in COS and CS2 catalytic hydrolysis reaction. The XPS results showed that most of products on the exhausted catalysts were S/SO42- species which accumulated on the active carbon’s surface and had a negative effect on the hydrolysis activity, and the contents of S/SO42- species of exhausted Fe–Cu–Ni/MCAC were higher than which of exhausted Fe–Cu–Ni/MCSAC catalysts.