Low-temperature hydrolysis of carbonyl sulfide in blast furnace gas using MgAl hydrotalcite catalysts with chlorine poisoning resistance

COS hydrolysis is an important aspect for the desulfurization of blast furnace gas (BFG). However, the MgAl-LDO hydrolysis catalyst always suffers from the low COS conversion and poisoning due to the low temperature (about 60 ℃) and the HCl containing. Herein, we proposed to modulate the catalyst structure and increase the number of basic sites and oxygen vacancies via heat treatment and N-doping. The N-LDO450 catalyst, which was prepared by heating at 450 ℃ under NH3 atmosphere, has an excellent COS hydrolysis catalytic and chlorine poisoning resistance. It shows a higher hydrolysis conversion of COS reaching 92% in the presence of HCl, whereas that of the A-LDO450 catalyst is only 71% under the same conditions. Heat treatment could optimize the catalyst's basicity and structural properties, and N-doping could facilitate the substitution of O atoms within the layers, generating oxygen vacancies, and thus bring the enhancement. The results could provide a valuable insight for the developing of COS hydrolysis catalyst suitable for the operation conditions of BFG.