24小时热门版块排行榜

>论坛更新日志 (3108)
>虫友互识 (769)
>文献求助 (191)
>休闲灌水 (148)
>导师招生 (136)
>考博 (128)
>教师之家 (81)
>找工作 (76)
>硕博家园 (74)
>博后之家 (73)
>论文投稿 (71)
>论文道贺祈福 (66)
>基金申请 (62)
>考研 (57)
>公派出国 (50)
>招聘信息布告栏 (32)

返回列表

当前只显示满足指定条件的回帖，点击这里查看本话题的所有回帖

feiba00

木虫 (小有名气)

应助: 13 (小学生)
金币: 2908.9
散金: 398
红花: 2
帖子: 288
在线: 167.1小时
虫号: 1615275
注册: 2012-02-13
性别: GG
专业: 电化学分析

[交流] 最新nature materials 燃料电池非铂氧还原催化剂已有7人参与

Identification of catalytic sites for oxygen reduction in iron- and nitrogen-doped graphene materials

Andrea Zitolo, Vincent Goellner, Vanessa Armel, Moulay-Tahar Sougrati, Tzonka Mineva, Lorenzo Stievano, Emiliano Fonda & Frédéric Jaouen
AffiliationsContributionsCorresponding authors

Abstract
Abstract• References• Author information• Supplementary information
While platinum has hitherto been the element of choice for catalysing oxygen electroreduction in acidic polymer fuel cells, tremendous progress has been reported for pyrolysed Fe–N–C materials. However, the structure of their active sites has remained elusive, delaying further advance. Here, we synthesized Fe–N–C materials quasi-free of crystallographic iron structures after argon or ammonia pyrolysis. These materials exhibit nearly identical Mössbauer spectra and identical X-ray absorption near-edge spectroscopy (XANES) spectra, revealing the same Fe-centred moieties. However, the much higher activity and basicity of NH3-pyrolysed Fe–N–C materials demonstrates that the turnover frequency of Fe-centred moieties depends on the physico-chemical properties of the support. Following a thorough XANES analysis, the detailed structures of two FeN4 porphyrinic architectures with different O2 adsorption modes were then identified. These porphyrinic moieties are not easily integrated in graphene sheets, in contrast with Fe-centred moieties assumed hitherto for pyrolysed Fe–N–C materials. These new insights open the path to bottom-up synthesis approaches and studies on site–support interactions.

回复此楼

» 本帖附件资源列表

欢迎监督和反馈：小木虫仅提供交流平台，不对该内容负责。
本内容由用户自主发布，如果其内容涉及到知识产权问题，其责任在于用户本人，如对版权有异议，请联系邮箱：xiaomuchong@tal.com
附件 1 : Identification_of_catalytic_sites_for_oxygen_reduction_in_iron-_and_nitrogen-doped_graphene_materials.pdf

2015-08-14 08:41:00, 891.66 K