Direct Synthesis of Pure H2O2 Aqueous Solution by CoTPP/Ketjen-Black Electrocatalyst and the Fuel Cell Reactor

作者：Iwasaki Tatsuya; Masuda Yukako; Ogihara Hitoshoi; Yamanaka Ichiro^*

来源：Electrocatalysis, 2018, 9(2): 236-242.

DOI：10.1007/s12678-017-0444-0

• Co-N-C compound electrocatalysis
• O-2 reduction
• H2O2
• Heat treatment

Hydrogen peroxide as an important and green oxidant for chemical process is manufactured by the anthraquinone (AQ) process, which is an indirect synthesis method and consumes a large quantity of energy. We have reported the direct and efficient synthesis of pure H2O2 aqueous solutions by O-2 and H-2 fuel-cell reactions using the Co-N-C compound cathode. Catalysis of Co-N-C-compound was improved in this work. Precursors of Co-N-C compounds were prepared by impregnation of 5,10,15,20-tetrakis(phenyl)-21H, 23H-porphyrin cobalt (II) (CoTPP) on various carbon materials. Effects of carbon materials, heat-treatment temperatures, Co loadings of the precursors on the electrocatalysis for H2O2 synthesis were studied from a current density (j), a H2O2 formation rate (R(H2O2)), a H2O2 concentration (C(H2O2)) and a faradic efficiency for H2O2 formation (FE(H2O2)). The most active and effective Co-N-C electrocatalyst is Ketjen-Black supported CoTPP (0.05 Co-wt%) activated at 1023 K in He stream as denoted 0.05 wt%/CoTPP/KB(1023 K) and shows a highest C(H2O2) and FE(H2O2) of 5.5 mol dm(-3) (18.7 wt%) and 55%, respectively, with a high Co turnover-frequency of 26 s(-1). Effects of amounts of the 0.05 wt%/CoTPP/KB(1023 K) electrocatalyst coated on the VGCF-base cathode were studied on the H2O2 synthesis and distributions of open-circuit voltages as electromotive forces to cathode and anode over-potentials and an IR-drop (VGCF: vapor-growing carbon fiber).

• 出版日期2018-3