Insights into the surface-defect dependence of molecular oxygen activation over birnessite-type MnO2
Author(s)
Yang, W
Zhu, Y
You, F
Yan, L
Ma, Y
Lu, C
Gao, P
Hao, Q
Li, W
Griffith University Author(s)
Year published
2018
Metadata
Show full item recordAbstract
In establishing the kinetics, energetics and mechanisms of phenolic degradation reactivity, active reactive oxygen species (ROS) on catalysts surface could exert a vital part. This paper attempts to account for different ROS at the atomic level using octahedral layered birnessite-type MnO2 as a platform with different crystal planes which could induce the Jahn-Teller effect and further realize deep mineralization of phenolic pollutants at low temperature. The catalytic degradation phenol rate of (100) MnO2 is 3 times as much as that of (001) MnO2, and the activation energy of the catalytic reaction is reduced by 11 KJ/mol. ...
View more >In establishing the kinetics, energetics and mechanisms of phenolic degradation reactivity, active reactive oxygen species (ROS) on catalysts surface could exert a vital part. This paper attempts to account for different ROS at the atomic level using octahedral layered birnessite-type MnO2 as a platform with different crystal planes which could induce the Jahn-Teller effect and further realize deep mineralization of phenolic pollutants at low temperature. The catalytic degradation phenol rate of (100) MnO2 is 3 times as much as that of (001) MnO2, and the activation energy of the catalytic reaction is reduced by 11 KJ/mol. The degradation content of (100) MnO2 surpasses 30% than that of (001) MnO2. Both spin-trapping EPR and DFT results show superoxide ([rad]O2−) species could exist on (001) MnO2 through one electron transfer, while the peroxide (O22−) species exist on (100) MnO2 via two electrons transfer. All the results illustrate that birnessite MnO2 possesses surface-dependent molecular oxygen activation properties.
View less >
View more >In establishing the kinetics, energetics and mechanisms of phenolic degradation reactivity, active reactive oxygen species (ROS) on catalysts surface could exert a vital part. This paper attempts to account for different ROS at the atomic level using octahedral layered birnessite-type MnO2 as a platform with different crystal planes which could induce the Jahn-Teller effect and further realize deep mineralization of phenolic pollutants at low temperature. The catalytic degradation phenol rate of (100) MnO2 is 3 times as much as that of (001) MnO2, and the activation energy of the catalytic reaction is reduced by 11 KJ/mol. The degradation content of (100) MnO2 surpasses 30% than that of (001) MnO2. Both spin-trapping EPR and DFT results show superoxide ([rad]O2−) species could exist on (001) MnO2 through one electron transfer, while the peroxide (O22−) species exist on (100) MnO2 via two electrons transfer. All the results illustrate that birnessite MnO2 possesses surface-dependent molecular oxygen activation properties.
View less >
Journal Title
Applied Catalysis B: Environmental
Volume
233
Subject
Physical chemistry
Chemical engineering
Environmental engineering