Understanding the Promotion Effect of Mn on CuO/Al2O3 for Catalyzed HCl Oxidation to Cl2

Abstract HCl oxidation to Cl 2 catalyzed by Cu‐based catalysis is an effective way to realize the sustainable development of chlorine‐involved industries. In this work, we investigated the role of promoter Mn on CuO/Al 2 O 3 in HCl oxidation to Cl 2 . The X‐ray diffraction (XRD), scanning electron microscopy (SEM), high‐resolution transmission electron microscopy (HRTEM) and H 2 ‐temperature programmed reduction (H 2 ‐TPR) characterizations suggested that Cu could be well dispersed in the MnO x lattice and hindered the reduction of CuO due to their strong interaction. The catalyst showed an unprecedentedly stable HCl conversion rate ( x HCl ) of about 79 % with space time yield (STY) of 2.14 g Cl2 g cat −1 h −1 in a 1000 hours test. The results of reaction kinetics suggested that the deep chlorination of catalysts was significantly inhibited under the reaction atmosphere. Density functional theory (DFT) calculations proved that the binding energy of O on CuO−MnO x /Al 2 O 3 ternary system was significantly strengthened that overwhelmed Cl, with ΔG O (−4.12 eV) ≪ ΔG Cl (‐1.75 eV), which greatly inhibited the poisoning of reactive sites by Cl*. A good correlation between experimental observations and theoretical calculations was established in this work.