Study of Direct Synthesis of Hydrogen Peroxide Acid Solutions at a Heat-Treated MnCl–Porphyrin/Activated Carbon Cathode from H₂ and O₂

Abstract

Heat-treated MnCl−porphyrin supported on activated carbon (AC) catalyzed electrochemical reduction of O 2 to H 2 O 2 using an H 2 /O 2 fuel cell reactor. Suitable preparation conditions for an Mn−porphyrin electrocatalyst were studied for the H 2 O 2 formation, such as types of porphyrin rings, heat-treatment temperatures in He, and Mn loadings. The effects of reaction conditions, H 2 SO 4 concentration, P(O 2 ), P(H 2 ), and electrolyte flow on the H 2 O 2 formation were studied. Then, 0.5 wt % MnCl−TPP/AC heat treated at 823 K and 0.3 wt % MnCl−OEP/AC heat treated at 723 K showed good electrocatalytic activities for the H 2 O 2 formation (TPP: 5,10,15,20-tetrakis-(phenyl)-21H,23H-porphyrin, OEP: 2,3,7,8,12,13,17,18-octaethyl-21H,23Hporphyrin). A maximum H 2 O 2 concentration of 1.0 mol dm −3 with 47% current efficiency (CE) was obtained under suitable conditions. The heattreated MnCl−TPP/AC and MnCl−OEP/AC electrocatalysts were characterized using temperature-programmed desorption, X-ray absorption near-edge structure spectroscopy, elemental analysis, cyclic voltammetry, and rotating ring-disk electrode voltammetry. Elimination of Cl from MnCl−TPP and MnCl−OEP supported on AC was essential to generate an active site for the H 2 O 2 formation. A model of the Mn active site was proposed.

Toward the Decentralized Electrochemical Production of H2O2: A Focus on the Catalysis

“…They also used graphitic carbon materials, vapor-grown carbon fibers (VGCF), 63 activated carbon with VGCF, 64 oxidized activated carbon with VGCF, 65,66 and metal-nitrogen/carbon (M-N/C) catalysts, Co-NX, [67][68][69] and Mn-NX. 71 Notably, several reports show that the oxidative treatment of carbon can yield higher rates of H2O2 production in a fuel cell configuration as well as in the electro-Fenton process. 51,65 Incorporating phenol groups onto carbon electrodes improves the rates of H2O2 production in a PEM electrolyser setup.…”

“…They tested 15 several different cathode catalysts, including vapor-grown carbon fiber (VGCF), 63 activated carbon with VGCF, 64 oxidized activated carbon with VGCF, 65,66 Co-NX, [67][68][69][70] and Mn-NX. 71 Using Co-NX/C as a cathode catalyst, Yamanaka and coworkers demonstrated that they could produce aqueous solutions of H2O2 at concentrations as high as 18.7 wt% H2O2, with a Faradaic efficiency of 55 %. 70 A key advantage of using the PEM configuration is that the H2O2 produced is H2O2 in pure water, as shown in Figure 6d.…”

燃料電池型反応器を用いた酸素，水素からの過酸化水素の直接かつ安全な合成法

“…CV studies were also not effective to obtain information about the electrochemical active site because the electric double layer of AC was so large and no difference was found in the CV data of Mn(OEP)Cl/AC(T) and only AC 25) . However, significant information was obtained for the active site structure by temperatureprogrammed-desorption (TPD) spectra of Mn(OEP)Cl/ AC.…”

“…However, significant information was obtained for the active site structure by temperatureprogrammed-desorption (TPD) spectra of Mn(OEP)Cl/ AC. Desorption products from the Mn(OEP)Cl/AC 25) . At higher pyrolysis temperatures, the porphyrin ring structure of Mn(OEP)/AC decomposed and electrocatalysis at the Mn site changed from twoelectron reduction to four-electron reduction of O2.…”

Electrochemically derived functionalized graphene for bulk production of hydrogen peroxide

“…The major roadblock in this method is the development of a sustainable electrocatalyst for the selective reduction of oxygen to H 2 O 2 [19][20][21][22][23]. Today, most electrochemical H 2 O 2 production methods rely on precious-metal-based materials or transition metal and/or metal oxides, and hence their economic viability for the future technologies is highly questionable [10,[24][25][26][27]. Hence new metal-free electrode materials for H 2 O 2 generation are highly sought after for future technologies.…”