Mn-based mullite-type oxides for air pollutant elimination from flue gas

The emission of gaseous pollutants such as NO_x, volatile organic compounds, and CO, is considered as one of the most serious challenges for the environment and climate. Catalytic oxidation has been regarded as one of the most promising technologies for pollutant elimination. Designing efficient catalysts is the major challenge of this technology. Transition-based oxides have been developed as promising candidates due to their low cost and abundance. Among these materials, Mn-based mullite-type oxide catalysts have attracted wide attention due to their special crystal structures, high thermal stability, and enhanced catalytic activities in recent years. Even though they were first synthesized in 2004, they were first used as pollutant elimination catalysts in 2012. Herein, this article systematically reviewed the applications and developments of mullite-type oxide catalysts in pollutant catalytic oxidation. Appropriate calcination temperature, calcination time, and a comparison of different synthetic methods were addressed. The application scenarios, influences of various reaction conditions, and related reaction mechanisms of pristine and modified Mn-based mullite-type oxide catalysts for pollutant catalytic oxidation were highlighted. In-depth study on the reaction mechanism of pollutant catalytic oxidation was analyzed. We hold a belief that this review can provide fundamental points and strategies for the further design and application of Mn-based mullite-type oxide catalysts.