Effects of acid treatments of activated carbon on its physiochemical structure as a support for copper oxide in DeSO2 reaction catalysts

To enhance the dispersion of active sites, modification of the AC supports with different acid solution might result in various surface oxygen groups which act as anchoring sites for metallic precursor to stay and improve the reactivity between AC supports and copper precursor. In the present work, the AC support is tailored with HCl and HNO3, respectively. The pore structure, surface oxygen groups of the AC support and catalysts as well as catalyst dispersion before and after acid treatments are systematically studied by BET, pHslurry, TPD, and XRPD analyses. It is found that the order of activity in DeSO2 reaction is as follows: Cu/AC–HCl > Cu/AC > Cu/AC–HNO3. The same sequence is also observed for the pore structure of AC supports, the catalyst dispersion, but not for the amounts of CO2 evolving during TPD experiments of supports. The key role of acid treatment on carbon surface chemistry and pore structure, which are closly related to catalyst dispersion and adsorption capacity, is examined to rationalize these findings. Furthermore, under the NO/NH3 = 1 the NO could be selective catalytic reduction with NH3 in the presence of O2, which catalyzed by fresh and spent AC-supported catalyst.