Highly efficient electrosynthesis of hydrogen peroxide on a superhydrophobic three-phase interface by natural air diffusion

Abstract

Hydrogen peroxide (H 2 O 2) synthesis by electrochemical oxygen reduction reaction has attracted great attention as a green substitute for anthraquinone process. However, low oxygen utilization efficiency (<1%) and high energy consumption remain obstacles. Herein we propose a superhydrophobic natural air diffusion electrode (NADE) to greatly improve the oxygen diffusion coefficient at the cathode about 5.7 times as compared to the normal gas diffusion electrode (GDE) system. NADE allows the oxygen to be naturally diffused to the reaction interface, eliminating the need to pump oxygen/air to overcome the resistance of the gas diffusion layer, resulting in fast H 2 O 2 production (101.67 mg h-1 cm-2) with a high oxygen utilization efficiency (44.5%-64.9%). Long-term operation stability of NADE and its high current efficiency under high current density indicate great potential to replace normal GDE for H 2 O 2 electrosynthesis and environmental remediation on an industrial scale.

Integrated and Superaerophilic Ni-O-C Electrode enables Fast and Stable Electrochemical H2O2 Production for Electro-Fenton-like Process

“…As shown in Fig. 3c The superaerophilic property of an electrode has already been demonstrated effective in accelerating the gas diffusion process, thereby greatly enhancing the current increasing rate in diffusion region 39 . In this case, a fast-current increase rate as well as a large current density was observed in the IS-NiOC electrode by virtue of the advantages of catalyst and architecture.…”

“…Direct construction of active materials into micro-/nanostructures on conductive substrates to form integrated electrodes may reinforce the gas diffusion channels to against the destruction. 38,39,43,44 As schemed in Fig. 1b, we hypothesize that the integrated and superaerophilic electrode establishes a dense and thick gas diffusion layer that can mitigate the H 2 O 2 corrosion process.…”

“…In contrast to tremendous progress in seeking for active catalysts, there are very limited efforts devoted to investigate advanced electrode architectures, which is equally important and nonnegligible as e cient electrode architectures can simultaneous accelerate electron and reactant transport rate. [37][38][39][40][41][42] The general strategy to solve this problem is employing a Te on-treated carbon ber paper (TCFP) as the substrate to increase three-phase contact point (TPCP) by constructing gas-diffusion layer, as shown in Fig. 1a.…”

Carbon‐based cathode materials for rechargeable zinc‐air batteries: From current collectors to bifunctional integrated air electrodes

“…Recently, research studies have focused on the controllable three‐phase interface design to facilitate the highly efficient air diffusion and material utilization with carbon fibers and uncomplex synthesis methods, 115,116 which are anticipated to have great potential in practical applications if they can further scale up.…”

Scaling-up of microbial electrosynthesis with multiple electrodes for in situ production of hydrogen peroxide

“…However, low oxygen utilization efficiency was a common phenomenon in which graphite plate was used as electrodes (Yu et al, 2015b). Recently, Zhang et al reported a superhydrophobic natural air diffusion electrode, which had an oxygen utilization efficiency of up to 65% when used in the synthesis of H 2 O 2 (Zhang et al, 2020). This provided a solution for the subsequent application of the scaled-up MES system to efficiently synthesize H 2 O 2 and further reduce the energy consumption caused by aeration.…”