title: Pd-catalytic in situ generation of H2O2 from H2 and O2 produced by water electrolysis for the efficient electro-fenton degradation of rhodamine B.
abstract: A novel electro-Fenton process was developed for wastewater treatment using a modified divided electrolytic system in which H2O2 was generated in situ from electro-generated H2 and O2 in the presence of Pd/C catalyst. Appropriate pH conditions were obtained by the excessive H+ produced at the anode. The performance of the novel process was assessed by Rhodamine B (RhB) degradation in an aqueous solution. Experimental results showed that the accumulation of H2O2 occurred when the pH decreased and time elapsed. The maximum concentration of H2O2 reached 53.1 mg/L within 120 min at pH 2 and a current of 100 mA. Upon the formation of the Fenton reagent by the addition of Fe2+, RhB degraded completely within 30 min at pH 2 with a pseudo first order rate constant of 0.109 ± 0.009 min(-1). An insignificant decline in H2O2 generation and RhB degradation was found after six repetitions. RhB degradation was achieved by the chemisorption of H2O2 on the Pd/C surface, which subsequently decomposed into •OH upon catalysis by Pd0 and Fe2+. The catalytic decomposition of H2O2 to •OH by Fe2+ was more powerful than that by Pd0, which was responsible for the high efficiency of this novel electro-Fenton process.
authors.affiliation: State Key Lab of Biogeology and Environmental Geology, China University of Geosciences , Wuhan, 430074, PR China. yuansonghu622@hotmail.com
authors.forename: Songhu
authors.initials: S
authors.lastname: Yuan
authors.forename: Ye
authors.initials: Y
authors.lastname: Fan
authors.forename: Yucheng
authors.initials: Y
authors.lastname: Zhang
authors.forename: Man
authors.initials: M
authors.lastname: Tong
authors.forename: Peng
authors.initials: P
authors.lastname: Liao
mesh_terms: D002384:Catalysis; D004560:Electricity; D004572:Electrolysis / Q000379:methods*; D004785:Environmental Pollutants / Q000302:isolation & purification; D006859:Hydrogen / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000138:chemical synthesis* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry; D008903:Minerals; D010100:Oxygen / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D012235:Rhodamines / Q000737:chemistry*; D013997:Time Factors; D014867:Water / Q000737:chemistry*
chemical_list: D004785:Environmental Pollutants; C045076:Fenton's reagent; D008903:Minerals; D012235:Rhodamines; D014867:Water; D010165:Palladium; D006859:Hydrogen; D006861:Hydrogen Peroxide; D007501:Iron; C029773:rhodamine B; D010100:Oxygen