In-Plane Topological-Defect-Enriched Graphene as an Efficient Metal-Free Catalyst for pH-Universal H 2 O 2 Electrosynthesis.
Zhixing MouYuewen MuLijia LiuDaili CaoShuai ChenWenjun YanHaiqing ZhouTing-Shan ChanLo-Yueh ChangXiujun FanPublished in: Small (Weinheim an der Bergstrasse, Germany) (2024)
Developing efficient metal-free catalysts to directly synthesize hydrogen peroxide (H 2 O 2 ) through a 2-electron (2e) oxygen reduction reaction (ORR) is crucial for substituting the traditional energy-intensive anthraquinone process. Here, in-plane topological defects enriched graphene with pentagon-S and pyrrolic-N coordination (SNC) is synthesized via the process of hydrothermal and nitridation. In SNC, pentagon-S and pyrrolic-N originating from thiourea precursor are covalently grafted onto the basal plane of the graphene framework, building unsymmetrical dumbbell-like S─C─N motifs, which effectively modulates atomic and electronic structures of graphene. The SNC catalyst delivers ultrahigh H 2 O 2 productivity of 8.1, 7.3, and 3.9 mol g catalyst -1 h -1 in alkaline, neutral, and acidic electrolytes, respectively, together with long-term operational stability in pH-universal electrolytes, outperforming most reported carbon catalysts. Theoretical calculations further unveil that defective S─C─N motifs efficiently optimize the binding strength to OOH * intermediate and substantially diminish the kinetic barrier for reducing O 2 to H 2 O 2 , thereby promoting the intrinsic activity of 2e-ORR.
Keyphrases
- room temperature
- ionic liquid
- hydrogen peroxide
- highly efficient
- metal organic framework
- carbon nanotubes
- nitric oxide
- walled carbon nanotubes
- reduced graphene oxide
- climate change
- high resolution
- binding protein
- visible light
- mass spectrometry
- solid state
- risk assessment
- heavy metals
- transcription factor
- electron microscopy