Defect-Rich Regulatory Activity Strategy: Disordered Structure for Enhanced Catalytic Interfacial Reaction of Chlorobenzene.

Abstract

In contrast to previous defect engineering methods, the preparation of amorphous materials can obtain abundant defect sites through a simple way, which is expected to effectively degrade Volatile Organic Compounds (VOCs) under milder conditions. However, in-depth and systematic studies in this area are still lacking. Novel types of amorphous CeMnx catalysts with abundant defects were prepared through simple hydrothermal synthesis and used for Cl-VOCs catalysis for the first time. Experimental characterizations and DFT calculations proved that Ce doping induced MnO2 lattice distortion, which led to the transformation of CeMnx into an amorphous structure and the formation of abundant defect sites. It was observed that CeMn0.16 was able to eliminate chlorobenzene (CB) at 200 °C, and the CO2 yields and the selectivity of inorganic chlorine was significantly higher than that of MnO2. The 18O isotope kinetic experiments revealed that the interfacial reaction process followed the MVK mechanism. The large number of oxygen vacancies accelerated the migration of lattice oxygen from the interior to the exterior, enhancing the ability to trap gas-phase oxygen. Mn4+ acted as the main active center to participate in CB catalysis, and the resulting reactive oxygen species (ROS) and Mn3+-[O2-]-Ce4+ further accelerated the entire oxidation cycle.