Briguglio, Nicola and Siracusano, Stefania and Bonura, Giuseppe and Sebastian, David and Aricò, Antonino Salvatore Flammability reduction in a pressurised water electrolyser based on a thin polymer electrolyte membrane through a Pt-alloy catalytic approach. Applied Catalysis B: Environmental.
|
Text
APCATB-S-18-05408.pdf - Accepted Version Download (5MB) | Preview |
Abstract
Various Pt-based materials (unsupported Pt, PtRu, PtCo) were investigated as catalysts for recombining hydrogen and oxygen back into water. The recombination performance correlated well with the surface Pt metallic state. Alloying cobalt to platinum was observed to produce an electron transfer favouring the occurrence of a large fraction of the Pt metallic state on the catalyst surface. Unsupported PtCo showed both excellent recombination performance and dynamic behaviour. In a packed bed catalytic reactor, when hydrogen was fed at 4% vol. in the oxygen stream (flammability limit), 99.5% of the total H 2 content was immediately converted to water in the presence of PtCo thus avoiding safety issues. The PtCo catalyst was thus integrated in the anode of the membrane-electrode assembly of a polymer electrolyte membrane electrolysis cell. This catalyst showed good capability to reduce the concentration of hydrogen in the oxygen stream under differential pressure operation (1-20 bar), in the presence of a thin (90 µm) Aquivion® membrane. The modified system showed lower hydrogen concentration in the oxygen flow than electrolysis cells based on state-of-the-art thick polymer electrolyte membranes and allowed to expand the minimum current density load down to 0.15 A cm -2 . The electrolysis cell equipped with a dual layer PtCo/IrRuOx oxidation catalyst achieved a high operating current density (3 A cm -2 ) as requested to decrease the system capital costs, under high efficiency conditions (about 77% efficiency at 55°C and 20 bar). Moreover, the electrolysis system showed reduced probability to reach the flammability limit under both high differential pressure (20 bar) and partial load operation (5%), as needed to properly address grid-balancing service.
| Item Type: | Article |
|---|---|
| Subjects: | 600 Tecnologia - Scienze applicate > 660 Ingegneria chimica |
| Depositing User: | Dr. Antonino Salvatore Aricò |
| Date Deposited: | 29 Sep 2020 14:50 |
| Last Modified: | 29 Sep 2020 14:50 |
| URI: | http://eprints.bice.rm.cnr.it/id/eprint/19225 |
Actions (login required)
 |
View Item |
