Boosting the efficiencies of ethanol total combustion by Cs incorporation into rod-shaped alpha-MnO2 catalysts

Herein, cesium was introduced into two kinds of rod-shaped alpha-MnO2 with different crystal facets by ion exchange technique, and the as-prepared four catalysts were used to evaluate their performance in the total combustion of ethanol with low concentration. When compared to undoped alpha-MnO2(211) and alpha-MnO2(310) catalysts, the Csdoped alpha-MnO2(211)-Cs and alpha-MnO2(310)-Cs catalysts showed significantly improved catalytic performance at a high space velocity (SV) (132,000 mL/(g.h)). Kinetic results demonstrate that in catalysts the activation energy (Ea) with Cs dopant is lower than without. The characterization results by various techniques such as XRD, ICP-OES, BET, FE-SEM, HR-TEM, H-2-TPR, NH3-TPD, XPS, and ethanol-TPD reveal that the introduction of Cs into alpha-MnO2 samples not only improves the low temperature reducibility but also contributes to the generation of more surface Mn4+ and oxygen vacancies, which are efficient in forming more reactive oxygen species, therefore, boosting ethanol oxidation activity. The incorporation of the alkali cation Cs+ into the alpha-MnO2 is an effective strategy in designing low-cost, high-performance, and environmentally friendly metal oxide combustion catalysts.

Automated summary

In this study, cesium was introduced into two rod-shaped alpha-MnO2 with different crystal facets by ion exchange technique, resulting in improved catalytic performance and lower activation energy. Characterization using various techniques revealed that Cs doping enhanced the reducibility of the catalysts and promoted the generation of more reactive oxygen species, boosting ethanol oxidation activity. Incorporating Cs+ into alpha-MnO2 proved to be an effective strategy for designing low-cost, high-performance, and environmentally friendly metal oxide combustion catalysts.