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Abstract Aldehyde‐assisted water electrolysis offers an attractive pathway for energy‐saving bipolar hydrogen production with combined faradaic efficiency (FE) of 200% while converting formaldehyde into value‐added formate. Herein we report the design and synthesis of noble metal‐free Cu6Sn5alloy as a highly effective electrocatalyst for formaldehyde electro‐oxidative dehydrogenation, demonstrating a geometric current density of 915 ± 46 mA cm−2at 0.4 V versus reversible hydrogen electrode, outperforming many noble metal electrocatalysts reported previously. The formaldehyde‐assisted water electrolyzer delivers 100 mA cm−2at a low cell voltage of 0.124 V, and a current density of 486 ± 20 mA cm−2at a cell voltage of 0.6 V without any iR compensation and exhibits nearly 200% faradaic efficiency for bipolar hydrogen production at 100 mA cm−2in 88 h long‐term operation. Density functional theory calculations further confirm the notably lowered barriers for dehydrogenation and Tafel steps on the Cu₆Sn₅ surface compared to Cu, underscoring its potential as a highly active catalyst.
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Stable Fe 2 P 2 S 6 Nanocrystal Catalyst for High‐Efficiency Water Electrolysis
Abstract A crucial step toward clean hydrogen (H2) energy production through water electrolysis is to develop high‐stability catalysts, which can be reliably used at high current densities for a long time. So far, platinum group metals (PGM) and their oxides, for example, Pt and iridium oxide (IrO2) have been well‐regarded as the criterion for hydrogen and oxygen evolution reactions (HER and OER) electrocatalysts. However, the PGM catalysts usually undergo severe performance decay during the long‐term operation. Herein, the in situ growth of iron phosphosulfate (Fe2P2S6) nanocrystals (NCs) catalysts on carbon paper synthesized by combing chemical vapor deposition with solvent‐thermal treatment is reported to show competitive performance and stability as compared to the state‐of‐the‐art PGM catalysts in a real water electrolyzer. A current density of 370 mA cm−2is achieved at 1.8 V when using Fe2P2S6NCs as bifunctional catalysts in an anion exchange membrane water electrolyzer. The Fe2P2S6NCs also show much better stability than the Pt‐IrO2catalysts at 300 mA cm−2for a continuous 24 h test. The surface generated FeOOH on Fe2P2S6is the real active site for OER. These results indicate that the Fe2P2S6NCs potentially can be used to replace PGM catalysts for practical water electrolyzers.
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- Award ID(s):
- 1851674
- PAR ID:
- 10458304
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Small Methods
- Volume:
- 4
- Issue:
- 6
- ISSN:
- 2366-9608
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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