Cathodic Performances of MnO2 Induced C/Ni Foam Electrode for H2O2

Abstract MnO 2 has been regarded as the key active species for the reduction of H 2 O 2 , and the catalytic performances of electrodes and the open circuit potential are related to the MnO 2 preparation. However, there is limited understanding of how the operation para-meters affect the MnO 2 preparation and utilization. The sol-gel method was used to prepare the MnO 2 and a suitable preparation process was determined via the orthogonal and single-factor experiments. The optimal preparation conditions were: n (citric acid): n (manganese acetate) = 0.5:1, initial concentration of reactant C 0 = 0.1M, pH ≈ 6, temperature of reaction was about 60℃. The X-ray spectroscopy and cyclic voltammetry confirm that MnO 2 by sol-gel method was termed as mixed crystal of α-MnO 2 and γ-MnO 2 . Excessive H 2 O 2 was detrimental to catalytic ability of electrode because of the self-decomposition reaction of H 2 O 2 . Operation conditions affect the polarizability, which was an important indicator of the catalytic performance of electrodes. In this study, a new C/MnO 2 /Ni foam cathode was constructed by combining MnO 2 with C(carbon), and the catalytic activity of the electrode was correlated with the content of MnO 2 and the concentration of H 2 O 2 , which provided a strategy for the design and operation optimization of MnO 2 cathode catalyst. The results show that the optimal concentration of H 2 O 2 is 0.3M, and the optimal mass fraction of MnO 2 in the electrode is 40%.