Reducing the cost of RuO 2 /TiO 2 catalysts is still one of the urgent challenges in catalytic HCl oxidation. In the present work, a Ce-doped TiO 2 supported RuO 2 catalyst with a low Ru loading was developed, showing a high activity in the catalytic oxidation of HCl to Cl 2 . The results on some extensive characterizations of both Ce-doped TiO 2 carriers and their supported RuO 2 catalysts show that the doping of Ce into TiO 2 can effectively change the lattice parameters of TiO 2 to improve the dispersion of the active RuO 2 species on the carrier, which facilitates the production of surface Ru species to expose more active sites for boosting the catalytic performance even under some harsh reaction conditions. This work provides some scientific basis and technical support for chlorine recycling.
Several Ru-Ti oxide-based catalysts were investigated for the catalytic oxidation of HCl to Cl2in this work. The active component RuO2was loaded on different titanium-containing supports by a facile wetness impregnation method. The Ru-Ti oxide based catalysts were characterized by XRD, N2sorption, SEM, TEM, H2-TPR, XPS, and Raman, which is correlated with the catalytic tests. Rutile TiO2was confirmed as the optimal support even though it has a low specific surface area. In addition to the interfacial epitaxial lattice matching and epitaxy, the extraordinary performance of Ru-Ti rutile oxide could also be attributed to the favorable oxygen species on Ru sites and specific active phase-support interactions. On the other hand, the influence of additive Ce on the RuO2/TiO2-rutile was studied. The incorporation of Ce by varied methods resulted in further oxidation of RuO2into RuO2δ+and a modification of the support structure. The amount of favorable oxygen species on the surface was decreased. As a result, the Deacon activity was lowered. It was demonstrated that the surface oxygen species and specific interactions of the Ru-Ti rutile oxide were critical to HCl oxidation.