Role of catalyst deposition strategies and carbon materials in the efficient electrochemical generation of hydrogen peroxide

This work explores the influence of three different simple coating methods, immersion, handmade and hot dripping, on the electrochemical generation of hydrogen peroxide (H 2 O 2 ). Among these methods, hot dripping and immersion require the use of a solvent (2-propanol), whereas the handmade method only requires the catalyst and polytetrafluoroethylene (PTFE). Different lignocellulosic-derived materials from Phragmites australis were evaluated and compared with the commercial benchmark (Carbon Black Vulcan XC72), with the aim of replacing this fossil fuel derivative with carbons synthesized from waste. The study provides insight into how both the coating method and the catalyst type affect the electrocatalytic performance of H 2 O 2 production. An extensive physicochemical characterization was carried out for both the catalysts and the fabricated electrodes. The H 2 O 2 generation and accumulation capability of the catalysts were assessed through surface electrochemical characterization and chronoamperometry experiments respectively. Among the three deposition methods studied, the handmade approach consistently achieved the highest H 2 O 2 accumulation for all catalysts. PA-NaOH achieved the highest accumulation (surpassing CB Vulcan), with 579 mg L -1 . A clear linear correlation was observed between H 2 O 2 accumulation and the zeta potential of the catalyst inks, with more efficient production observed for zeta potentials closer to zero. This can be attributed to the enhanced formation of the *OOH reaction intermediate, as a higher proportion of protonated sites is expected in these materials. These results highlight the importance of the catalyst coating method and provide guidance for the design of electrodes aimed at maximizing the performance of electrochemical H 2 O 2 synthesis. • Three deposition methods for the 2e-ORR and four carbon catalysts were studied • Handmade gave best results in an undivided cell, reaching 579 mg L -1 • Catalysts with zeta potential near zero achieved the best performance • A linear trend between zeta potential and H 2 O 2 accumulation was observed • NaOH-activated Phragmites australis outperformed commercial CB Vulcan