摘要
Pd/C catalyst used for the Pd/C gas diffusion cathodes was prepared by hydrogen reduction method and formaldehyde reduction method, and characterized by X-ray diffraction (XRD), transmission elec- trode microcopy (TEM), X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry (CV) tech- niques. The electrochemical degradation of 4-chlorophenol was investigated in the diaphragm elec- trolysis system, aerating firstly with hydrogen gas then with air, using three different kinds of gas dif- fusion cathode. The results indicated that the self-made Pd/C gas diffusion cathode can not only re- ductively dechlorinate 4-chlorophenols by aerating hydrogen gas, but also accelerate the two-electron reduction of O2 to hydrogen peroxide (H2O2) by aerating air. Therefore, the removal efficiency of 4-chlorophenol by using Pd/C gas diffusion cathode is better than that of the C/PTFE gas diffusion cathode (no catalyst). The catalytic activity of Pd/C catalyst prepared by hydrogen reduction method is higher than that prepared by formaldehyde reduction method. The stability of the Pd/C gas diffusion cathodes is good. Therefore, both the removal efficiency and the dechlorination degree of 4-chlorophenol reached about 100% after 60 min, and the removal efficiency of 4-chlorophenol in terms of chemical oxygen demand (COD) in the cathodic compartment reached 87.4% after 120 min.
Pd/C catalyst used for the Pd/C gas diffusion cathodes was prepared byhydrogen reduction method and formaldehyde reduction method,and characterized by X-ray diffraction(XRD),transmission electrode microcopy (TEM),X-ray photoelectron spectroscopy (XPS),and cyclicvoltammetry (CV) techniques.The electrochemical degradation of 4-chlorophenol was investigated inthe diaphragm electrolysis system,aerating firstly with hydrogen gas then with air,using threedifferent kinds of gas diffusion cathode.The results indicated that the self-made Pd/C gas diffusioncathode can not only re-ductively dechlorinate 4-chlorophenols by aerating hydrogen gas,but alsoaccelerate the two-electron reduction of O2 to hydrogen peroxide (H2O2) by aeratingair.Therefore,the removal efficiency of 4-chlorophenol by using Pd/C gas diffusion cathode is betterthan that of the C/PTFE gas diffusion cathode (no catalyst).The catalytic activity of Pd/C catalystprepared by hydrogen reduction method is higher than that prepared by formaldehyde reductionmethod.The stability of the Pd/C gas diffusion cathodes is good.Therefore,both the removalefficiency and the dechlorination degree of 4-chlorophenol reached about 100% after 60 min,and theremoval efficiency of 4-chlorophenol in terms of chemical oxygen demand (COD) in the cathodiccompartment reached 87.4% after 120 min.
基金
Supported by the National Natural Science Foundation of China (Grant Nos. 50325824, 50678089)
China Postdoctoral Science Foundation (Grant No. 20060390454)
the Excellent Young Teacher Program of MOE, P. R. China
