Hydrothermal synthesis of MgAlZnFeCe hydrotalcite-like precursors and their complex oxides for application in FCC De-SO_x

MgAlZnFeCe hydrotalcite-like precursors were prepared by a hydrothermal method using MgO as magnesium resource and pseudoboehmite as aluminum resource, and using metal chlorides of Zn, Fe and Ce as catalytic additives. MgAlZnFeCe complex oxides were prepared by decomposition of MgAlZnFeCe hydrotalcite-like precursors at 700°C for 6 h, which were used for the removal of SO_x from FCC flue gas. XRD, TG-DTA analysis show that hydrotalcite-like compound is the major component while the minor phase is Mg(OH)₂ as the impure phase. The results of SO_x adsorption-reduction test show that the novel catalyst MgAlZnFeCe-LDO reaches 1.16 g/g of total saturation adsorption capacity in 10 min in the condition similar to that of a typical FCC, which achieves high oxidative adsorption rate, short saturation time, and large reductive capacity.