A novel trickle bed electrochemical reactor design for efficient hydrogen peroxide production

A specific and environmentally benign electrochemical reactor that combines the property of gas diffusion electrode (GDE) with trickling flow property in trickle bed electrochemical reactor (TBER) is designed for intensive hydrogen peroxide (H2O2) production. Compared with other reactors a significant feature of this reactor is the capability to uniformly distribute the oxygen gas all over the cathode bed avoiding oxygen gas transport limitations, electrode limited area, and continuous electrolyte leakage. This reactor consists of two plates as anodes and two porous layers composed of carbon black and polytetrafluoroethylene (C-PTFE) mixture that are pasted on two stainless steel meshes(SSM) to form cathode beds (C-PTFE-SSM). The cathodes are placed on both cathode frame sides which were designed to comprise two separated cathodes. The oxygen gas can flow easily through the space between cathodes and diffuses to the solid-liquid interface to be electrochemically reduced to form H2O2. H2O2 was in situ electrosynthesized in an alkaline solution by the oxygen electrochemical reduction on the cathode surface. All operating conditions that affect the process were systematically investigated. The highest concentration of H2O2 of 46.56 mM was achieved in 40 min and 1.0 V at room temperature, whereas at 0 ? the generated peroxide was 57.86 mM. This significant performance is attributed to the uniform oxygen distribution on the electrode bed making an easy access for gas transport to the electrolyte-cathode interface. The low temperature increases oxygen solubility which increases the production rate as well. Power consumption was also estimated and found to be 4 kWh/kg which is economically beneficial. At different applied cell voltages and best-operating conditions, a kinetic study was conducted for H2O2 electrosynthesized.

Automated summary

A specific electrochemical reactor combining gas diffusion electrode with trickling flow property is designed for intensive H2O2 production. The reactor allows uniform distribution of oxygen gas all over the cathode bed, avoiding transport limitations and electrode limited area. The highest concentration of H2O2 achieved was 46.56 mM, and the power consumption was estimated to be 4 kWh/kg, showing economic benefits.