Iridium black powder has been synthesized by chemical reduction of H2IrCl6x6H2O using NaBH4 as chemical reducer according to Ref. [1]. The electrocatalyst has been evaluated in a single cell polymer electrolyte membrane water electrolyser (PEMWEs) of 5 cm2, based on Aquivion® membrane and 30% Pt/C as cathode catalyst [2, 3]. The oxygen evolution catalysts based on Ir was directly deposited onto one side of the Aquivion® membrane by a spray coating technique. Inks were composed of aqueous dispersions of catalyst, deionized water, Aquivion ionomer and ethanol (Carlo Erba); the anode catalyst loading was 0.4 mg·cm-2. A Ti mesh was used as backing layer. A commercial 30% Pt/Vulcan XC-72 (ETEK, PEMEAS, Boston, USA) was used as the catalyst for the H2 evolution. The cathode electrode was prepared by directly mixing in an ultrasonic bath a suspension of Aquivion ionomer in water with the catalyst powder. The obtained cathode paste was spread on carbon cloth backings (GDL ELAT from ETEK) with a Pt loading of 0.1 mg·cm-2. The ionomer content in the electrodes was 20% and 33% by mass for the anode and cathode respectively. MEAs were directly prepared in the cell housing by tightening at 2 Nm using a dynamometric wrench. The single cell was investigated by using linear sweep voltammetry, electrochemical impedance spectroscopy and chrono-potentiometric measurements. The electrochemical activity of this MEA was analyzed in a temperature range from 25° to 90°C. The properties of this electrocatalyst have been investigated with the help of both ex-situ characterization and in-situ electrochemical diagnostics.
Performance of a PEM water electrolyser based on metallic iridium electrocatalyst and an Aquivion membrane
S Siracusano;V Baglio;A S Arico
2016
Abstract
Iridium black powder has been synthesized by chemical reduction of H2IrCl6x6H2O using NaBH4 as chemical reducer according to Ref. [1]. The electrocatalyst has been evaluated in a single cell polymer electrolyte membrane water electrolyser (PEMWEs) of 5 cm2, based on Aquivion® membrane and 30% Pt/C as cathode catalyst [2, 3]. The oxygen evolution catalysts based on Ir was directly deposited onto one side of the Aquivion® membrane by a spray coating technique. Inks were composed of aqueous dispersions of catalyst, deionized water, Aquivion ionomer and ethanol (Carlo Erba); the anode catalyst loading was 0.4 mg·cm-2. A Ti mesh was used as backing layer. A commercial 30% Pt/Vulcan XC-72 (ETEK, PEMEAS, Boston, USA) was used as the catalyst for the H2 evolution. The cathode electrode was prepared by directly mixing in an ultrasonic bath a suspension of Aquivion ionomer in water with the catalyst powder. The obtained cathode paste was spread on carbon cloth backings (GDL ELAT from ETEK) with a Pt loading of 0.1 mg·cm-2. The ionomer content in the electrodes was 20% and 33% by mass for the anode and cathode respectively. MEAs were directly prepared in the cell housing by tightening at 2 Nm using a dynamometric wrench. The single cell was investigated by using linear sweep voltammetry, electrochemical impedance spectroscopy and chrono-potentiometric measurements. The electrochemical activity of this MEA was analyzed in a temperature range from 25° to 90°C. The properties of this electrocatalyst have been investigated with the help of both ex-situ characterization and in-situ electrochemical diagnostics.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
