Synthesis of α–MnO2–like rod catalyst using YMn2O5 A–site sacrificial strategy for efficient benzene oxidation

Abstract

The elimination of benzene, a typical volatile organic pollutant, is one of the most challenging topics for environmental scientists. Catalytic oxidation technology is considered the most efficient approach for its elimination. Herein, we report the successful preparation of a novel α–MnO2–like rod catalyst via an acid etching route and propose YMn2O5 mullite as a novel precursor. The optimized α–MnO2–like rod catalyst showed significantly improved benzene oxidation activity compared to the raw YMn2O5 and commercial MnO2 catalysts, resulting in 100 % benzene conversion at 200 °C at a GHSV of 60,000 mL g–1 h–1. Notably, the α–MnO2–like rod catalyst performance at lower temperatures (100–175 ℃) exceeded that of a commercial Pt/Al2O3 catalyst. The excellent catalytic performance of the α–MnO2–like rod catalyst is associated with its low–temperature reducibility and abundant surface–active oxygen species. During the acid etching process, more Mn3+ is oxidized to Mn4+, and more surface oxygen vacancies are generated on the α–MnO2–like rod catalyst, which provides more adsorption sites for oxygen molecules to promote the benzene oxidation reaction. The α–MnO2–like rod catalyst should be a great alternative to commercial noble metal catalysts for the elimination of volatile organic pollutants, especially at lower temperatures.