Enabling direct H2O2 electrosynthesis of 100 % selectivity at 100 mA cm−2 using a continuous flow sulfite/air fuel cell

A sulfite/air fuel cell for H2O2 electrosynthesis

“…The discharge current continuously decreased during the running, ascribed to the decrease in the SO 3 2− concentration of the anolyte and accumulation of H 2 O 2 in the catholyte. 18 The ESR spectrum in Fig. 8(b) indicates a typical signal of a DMPO-• OH radical adduct, which confirmed the electrosynthesis of H 2 O 2 .…”

“…8 The cathodic side reaction of H 2 O 2 decomposition not only restricts the H 2 O 2 concentration but also consumes the applied electric charge. 18,38 Nevertheless, the potentiostat test demonstrates the feasibility of the self-driven fuel cell for H 2 O 2 electrosynthesis, which can produce electricity and H 2 O 2 simultaneously.…”

“…The RRDE consists of a platinum ring electrode (0.136 cm 2 ) and a glass carbon disc electrode (0.125 cm 2 ), whose collection efficiency was 0.37. 18 A platinum foil was used as the counter electrode. A saturated calomel reference electrode (SCE) was adopted.…”

“…50 mg catalyst, 10 mg polytetrafluoroethylene (PTFE) binder, and 2 mL isopropanol were mixed to prepare the catalyst ink, which was dispersed by ultrasonication and shaking. 18 The polarization curves were measured in O 2 -saturated 0.5 mol L −1 H 2 SO 4 at 5 mV s −1 . The temperature was 25 °C.…”

“…1, the cell consists of three acrylic channels, an SO 3 2− oxidation anode, an ORR cathode, and a Fumasep®FKD-PK-75 cation exchange membrane. 18 The square work area was 4 cm 2 . 20% Pd/C catalyst was applied as the SO 3 2− oxidation catalyst.…”