Chlorine-Tolerant Chlorobenzene Combustion over Mullite Catalysts via Constructing Ru-O-Mn Sites.

The catalytic combustion of chlorine-containing volatile organic compounds (CVOCs) at low temperatures still faces chlorine poisoning challenges. Herein, chlorine-tolerant chlorobenzene combustion over manganese-based mullite (SmMnO) catalysts has been originally demonstrated via constructing rich Ru-O-Mn sites, engineered from the doping of ruthenium (Ru) and the subsequent etching of samarium (Sm). Such catalysts exhibited 90% activity for chlorobenzene combustion at 258 °C and maintained about 80% activity after the 30 h stability test. Specifically, the doping of Ru could readily replace Mn of SmMnO to form Ru-O-Mn sites, and the etching of Sm could expose more surface Ru-O-Mn sites, which significantly enhanced the redox capacity and oxygen activation ability, thus improving the low-temperature catalytic combustion of chlorobenzene. Besides, the Ru-O-Mn sites boosted the transformation of chlorine-containing intermediate species to low-pollution species and accelerated the removal of Cl and the formation of CO, thus enhancing the chlorine tolerance of mullite catalysts. This study deepened the understanding of the catalytic combustion mechanism and provided a feasible strategy for the development of high-efficiency and chlorine-resistant catalysts for the catalytic combustion of CVOCs.