Enhanced Electroreductive Removal of Bromate by a Supported Pd-In Bimetallic Catalyst: Kinetics and Mechanism Investigation.
In this work, the electroreductive removal of bromate by a Pd1-In4/Al2O3catalyst in a three-dimensional electrochemical reactor was investigated. A total of 96.4% of bromate could be efficiently reduced and completely converted into bromide within 30 min under optimized conditions. On the basis of the characterization results and kinetics analysis, a synergistic effect of Pd and In was observed, and Pd1-In4/Al2O3had the highest reaction rate constant of 0.1275 min-1(vs 0.0413, 0.0328, and 0.0253 min-1for In/Al2O3, Pd/Al2O3, and Al2O3). The results of electron spin resonance and scavenger experiments confirmed that both direct electron transfer and indirect reduction by atomic H* were involved in the bromate removal process, while the direct reduction played a more important role. Moreover, the introduction of In could increase the zeta potential of Pd1-In4/Al2O3, facilitating bromate adsorption and its subsequent reduction on the catalyst. Finally, a reaction mechanism for bromate reduction by Pd1-In4/Al2O3was proposed based on all the experimental results.
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China.
Huachun
H
Lan
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China.
Ran
R
Mao
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China.
Yating
Y
Tong
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China.
Yanzhen
Y
Liu
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China.
Huijuan
H
Liu
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China.
Xiaoqiang
X
An
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China.
Ruiping
R
Liu
D000327:Adsorption; D001959:Bromates / Q000737:chemistry*; D001965:Bromides; D002384:Catalysis; D007700:Kinetics
D001959:Bromates; D001965:Bromides