Study of high-entropy oxides loaded activated carbon for removal of SO2 from flue gas

Abstract

High-entropy oxides (HEOs) is a new type of catalyst that has emerged in recent years. High-entropy oxides, which is doped by a variety of metal cations and form a single-phase solid solution with a uniquely stabilized structure, is a strong contender for ideal catalysts due to their elemental versatility and designability. However, high-entropy oxides (HEOs) had not yet emerged in the field of gas-phase catalysis, here we reported the selection of five metal salts Zn(NO3)2·6H2O, Cu(NO3)2·3H2O, Co(NO3)2·6H2O, Ni(NO3)2·6H2O and Fe(NO3)3·9H2O, a high-entropy oxide FeNiCuZnCoOx was successfully prepared and uniformly loaded on activated carbon using wet chemistry, it was applied to the catalytic oxidation and removal of SO2 in industrial flue gas, and the structural mechanism of HEOs affecting desulfurization capacity was described. The oxygen vacancy structure produced by the typical lattice distortion effect of high-entropy oxides greatly improved the catalytic activity of activated carbon, and the desulfurization capacity was significantly improved, in which the maximum saturated adsorption reached 40.93 mg/g at 293 K.