Improving the Efficiency of Carbon Cloth for the Electrogeneration of H₂O₂: Role of Polytetrafluoroethylene and Carbon Black Loading

Abstract

In this work, H2O2 is electro-generated in the cathodic compartment of a divided filterpress cell with a carbon cloth in the configuration of a gas diffusion electrode using air as oxygen source. The effect of Teflon ® content was studied and it was found that the appropriate content is within the range of 10-20%. The production was greatly enhanced after the air-brushing deposition (and subsequent annealing) of simply 0.5 mg of carbon black. Higher additions clogged the pores and resulted counterproductive in terms of H2O2 generation. At a current density of 25 mA cm -2 , the production rate was 15 mg H2O2 h -1 cm -2 with a current efficiency close to 100%. Production rate increased with current density up to more than 40 mg H2O2 h -1 cm -2 at 87.5 mA cm -2 . The good performance and ease of preparation of this electrode make it an interesting alternative to generate hydrogen peroxide for Electro-Fenton processes.

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

“…In addition to the oxygen mass transfer efficiency of the diffusion layer, the hydrophobicity/hydrophilicity of the catalytic layer interface exerted significant effects on the cathode performance. A more hydrophobic cathode surface that favored the O 2 transfer to the reaction interface was responsible for fast ORR rates 40 .…”

“…On the other hand, when the catalyst loading was too high, the thickness of the catalytic layer increased, and the oxygen diffusion capacity within the electrode was limited, resulting in the effect on ORR performance 27,56 . Peŕez et al reported that the increasing loading of the catalyst caused an important diffusion resistance and a sharp decrease in the oxygen supplied to the reaction interface, slowing down the reaction rate of H 2 O 2 electrosynthesis 40 . When the catalyst loading was as low as 1-2 mg cm −2 , although the current efficiency was slightly reduced, NADE also had excellent H 2 O 2 production efficiency with the current efficiency of about 80% at 10 min ( Supplementary Fig.…”

Photo-assisted electrochemical advanced oxidation processes for the disinfection of aqueous solutions: A review

“…For this purpose, electrodes made of carbonaceous materials such as carbon fibers, carbon felts and reticulated carbon vitreous are commonly used due to their high superficial area, high overpotential for H 2 evolution and to their low catalytic activity for H 2 O 2 reduction ( Bañuelos et al., 2016 ; García-Rodríguez et al., 2016 ; Mousset and Dionysiou, 2020 ; Pérez et al., 2017a ; Zárate-Guzmán et al., 2019 ; Zhou et al., 2018 ). Furthermore, the performance of the carbonaceous cathodes towards H 2 O 2 generation can be improved by the addition of PTFE and carbon black ( Jiao et al., 2020 ; Pérez et al, 2017b , 2019 ; Zhang et al., 2020c ; Zhao et al., 2019 ).…”

Enhanced electrocatalytic activity for H2O2 production by the oxygen reduction reaction: Rational control of the structure and composition of multi-walled carbon nanotubes

“…However, the high cost of precious metals could limit the bulk use of these catalysts. As a matter of fact, it is widely believed that carbonaceous materials are the most suitable alternatives as cathodic catalysts to produce H2O2 from the ORR, due to their advantages in terms of catalytic selectivity, cost, and environmental compatibility [23][24][25]. Recent papers have reported the use of N-doped non-metallic carbon materials [26,27] or non-noble metal and carbon gel complexes [28] for the electrochemical generation of H2O2.…”