Keggin型缺位杂多阴离子PW_(11)O_(39)^(7-)电催化降解硝基苯

Electrocatalytic Degradation of Nitrobenzene by Keggin-type Lacunary Heteropolyanion PW_(11)O_(39)^(7-)

以Keggin型缺位杂多阴离子PW11O397-(PW11)为电催化剂,硝基苯(NB)为模型污染物,研究了Na2SO4-NaHSO4介质中PW11O397-对NB的电催化降解作用.实验结果表明,在pH=2.5,E=-0.6V和O2流速为60mL·min-1的条件下,初始浓度为0.5mmol·L-1的硝基苯反应80min即完全降解,反应120min总有机碳(TOC)去除达42%.硝基苯的电催化降解服从准一级反应动力学模型,室温下其表观速率常数kobs的大小与NB的初始浓度有关,当NB的初始浓度为0.5,0.9和1.3mmol·L-1时,kobs值分别为1.0×10-1,6.0×10-2和4.1×10-2min-1.

With Keggin-type lacunary heteropolytungstate anion PW1 1 O 397― as an electrocatalyst and nitrobenzene （NB） as a model pollutant the electrocatalytic degradation of NB by PW1 1O 397― in Na2SO4＋ NaHSO4 medium was studied. Experimental results revealed that a complete NB degradation was obtained in less than 80 min in pH 2.5 Na2SO4-NaHSO4 solution containing 0.5 mmol·L-1 NB at the potential of-0.6 V and the O2 flow rate of 60 mL·min-1. A total organic carbon （TOC） removal reached 42% at 120 min reaction time. The NB degradation reaction followed the pseudo-first order kinetic regime and the observed rate constants kobs related to the initial NB concentration at room temperature was determined to be 1.0×10-1, 6.0×10-2 and 4.1×10-2 min-1 corresponding to 0.5, 0.9 and 1.3 mmol·L-1 initial NB concentrations, respectively.