The presence of molecular monolayers on semiconductor surfaces can improve the stability of semiconductor interfaces by inhibiting the growth of native oxides and defects which affect the materials’ electronic properties. The development of catalytically active passivated interfaces on semiconductor materials presents a useful material design for value‐added product conversion. Herein, an iron‐based catalyst covalently attached to silicon (Si) is reported for the investigation of activity and electrochemical decomposition pathways of diiron hydrogenase enzyme mimics. The employed catalyst, Fe2(CO)6(µ‐S‐C6H4‐p‐OH)2([FeFe]), mimics the active sites of these enzymes. Surface modification using this catalyst passivates the interface, hindering the formation of native SiO2for more than 300 h. [FeFe] modification improves the overpotential required to produce 10 mA cm–2by 100 mV, with a hydrogen evolution rate of 2.31 × 10–5 mol h–1 cm–2 (−0.78 V versus RHE). However, structural rearrangement transpires within 1 h of electrolysis, where Fe‐S bond dissociates at the catalytic center, resulting in an aromatic linkage modified Si interface. While semiconductor−catalyst interfaces have often been reported in the literature, their decomposition pathways have received limited discussion. Herein, this Si−[FeFe] interface is used as a tool for understanding the activity and decomposition mechanisms of the attached molecular catalyst.
This content will become publicly available on September 6, 2025
The performance of electrocatalysts is critical for renewable energy technologies. While the electrocatalytic activity can be modulated through structural and compositional engineering following the Sabatier principle, the insufficiently explored catalyst-electrolyte interface is promising to promote microkinetic processes such as physisorption and desorption. By combining experimental designs and molecular dynamics simulations with explicit solvent in high accuracy, we demonstrated that dimethylformamide can work as an effective surface molecular pump to facilitate the entrapment of oxygen and outflux of water. Dimethylformamide disrupts the interfacial network of hydrogen bonds, leading to enhanced activity of the oxygen reduction reaction by a factor of 2 to 3. This strategy works generally for platinum-alloy catalysts, and we introduce an optimal model PtCuNi catalyst with an unprecedented specific activity of 21.8 ± 2.1 mA/cm2at 0.9 V versus the reversible hydrogen electrode, nearly double the previous record, and an ultrahigh mass activity of 10.7 ± 1.1 A/mgPt.
more » « less- Award ID(s):
- 1931587
- PAR ID:
- 10552705
- Publisher / Repository:
- AAAS
- Date Published:
- Journal Name:
- Science Advances
- Volume:
- 10
- Issue:
- 36
- ISSN:
- 2375-2548
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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