Unique electron reservoir properties of manganese in Mn(II)-doped CeO2 for reversible electron transfer and enhanced Fenton-like catalytic performance

Abstract

Developing high-performance heterogeneous Fenton-like catalyst and understanding its intrinsic catalytic properties are of fundamental and practical significance. In this work, a mesoporous Mn(II)-doped CeO2 (MCO) with monodisperse spherical morphology and large surface area (141.8 m2 g−1) was fabricated through a simple hydrothermal–calcination process, and further utilized as the heterogeneous catalyst for oxidative degradation of organic pollutants in the presence of H2O2. The density functional theory (DFT) simulations were carried out to study the H2O2 decomposition process on the MCO surface. It was revealed that the Mn(II) doping in the CeO2 could significantly promote the complex of the surface Ce sites and H2O2 molecules. More importantly, the manganese dopants could serve as electron reservoirs, capable of reversibly donating and accepting electrons, which facilitated the electron transfer between Ce and H2O2. Owing to the electron reservoir properties of manganese, this MCO showed significantly enhanced catalytic efficiency in comparison to pure CeO2. Moreover, the catalytic activity of MCO almost kept unchanged after reuse several times, demonstrating its long-circulating characteristics. This study provides new and important insights into the electron transfer pathway involved in the heterogeneous Fenton-like process.