Hydrogen evolution on graphite/sulfonated polyether ether ketone (SPEEK) surface using zirconium oxide-stabilized cerium oxide nanocomposites

Abstract

The study examined the potential of sulfonated polyether ether ketone (SPEEK) combined with cerium oxide (CeO 2 ) and zirconium oxide (ZrO 2 ) nanocomposites for hydrogen production on a graphite substrate in an acidic environment. Among the various electrocatalytic compositions evaluated, the CeO 2 -ZrO 2 nanocomposite achieved remarkable efficiency at a 1:1 ratio, reaching a current density of 2000 mA/cm 2 on a geometrical area of 0.196429 cm 2 , a value considered superior to the majority of findings reported in the literature to date. This performance can be attributed to the distinctive morphology and surface area characteristics of the nanocomposites, with a BET surface area of 63.406 m 2 /g and an electrochemically active surface area (ECSA) of 4.4 cm 2 . In this system, SPEEK served a dual role of a protective membrane (Ecorr = −0.33 V vs −0.29 V) and a binder for the inorganic materials. When compared to platinum (Pt), the electrocatalysts exhibited commendable performance, showing only a 2.56 % deviation in the current. The hydrogen generation rate adhered to first-order kinetics, with a rate of 9.611 × 10 −5 A/s and a rate constant of 8.35 × 10 −5 s −1 . These findings underscore the significant potential of the SPEEK/CeO 2 -ZrO 2 nanocomposite system as a viable candidate for hydrogen production enhancement. • Generation of H2 on SPEEK/Ce:Zr surface is reported. • H 2 was produced at a rate of −9.6 × 10 −5 A/s with a rate constant of 8.4 × 10 −5 s −1 . • SPEEK served as inorganic species binder on the electrode's surface. • A current density of 2000 mA/cm 2 was realized with electrode diameter of 0.5 cm. • The current electrode exhibited better H 2 generation than conventional electrodes.