Mechanistic and Experimental Study of the CuxO@C Nanocomposite Derived from Cu-3(BTC)(2) for SO2 Removal

A tunable and efficient strategy was adopted to synthesize highly porous nano-structured CuO-carbonized composites (CuxO@C) using Cu-3(BTC)(2) as a sacrificial template. The as-synthesized CuO nanocomposites exhibited hollow octahedral structures, a large surface area (89.837 m(2) g(-1)) and a high proportion of Cu2O active sites distributed on a carbon frame. Based on DFT calculations, both the Cu atoms on the surface (Cu-S) and oxygen vacancy (O-V) exhibited strong chemical reactivity. On the perfect CuO (111), the Cu-S transferred charge to O atoms on the surface and SO2 molecules. A strong adsorption energy (-1.41 eV) indicated the existence of the chemisorption process. On the oxygen-deficient CuO (111), the O-2 preferably adsorbed on O-V and then formed SO3 by bonding with SO2, followed by the cleavage of the O-O bond. Furthermore, the CuO nanocomposites exhibited an excellent ratio of S/Cu in SO2 removal experiments compared with CuO nanoparticles produced by coprecipitation.