Online evaluation of the catalytic performance of MnO2 and its application in H2S cataluminescence sensing

Abstract

As a catalyst widely used in industry, manganese dioxide (MnO2) has different crystalline forms and shows excellent performance in catalytic reactions. Therefore, it is of significance to rapidly evaluate the catalytic performance of MnO2 online. In this paper, a highly efficient evaluation method based on H2S cataluminescence (CTL) sensing was proposed for MnO2 with different crystalline forms. Firstly, α-, β- and δ-MnO2 were synthesized successfully and performed diacritical CTL behaviours in the catalytic oxidation of H2S. Based on these interesting phenomena, the catalytic performance of α-, β- and δ-MnO2 was efficiently evaluated online through CTL method for the first time. Results showed that β-MnO2 had the best catalytic oxidation performance, followed by α- and δ-MnO2, and the reactive oxygen species of MnO2 was the most significant influencing factor. Subsequently, β-MnO2 was selected to design a CTL sensor for H2S detection with a wide linear range (2.43–29.1 μg/mL) and a low limit of detection (LOD, S/N = 3, 0.280 μg/mL). This work not only provided a new and feasible method for online evaluation of the catalytic performance of materials, but also designed a CTL sensor for H2S determination with high selectivity and sensitivity.