• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Advanced energy materials >Facile Metal Coordination of Active Site Imprinted Nitrogen Doped Carbons for the Conservative Preparation of Non-Noble Metal Oxygen Reduction Electrocatalysts
【24h】

Facile Metal Coordination of Active Site Imprinted Nitrogen Doped Carbons for the Conservative Preparation of Non-Noble Metal Oxygen Reduction Electrocatalysts

机译：活性位点氮掺杂碳的保守金属配位用于非贵金属还原氧电催化剂的保守制备

获取原文
获取原文并翻译 | 示例
       
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Iron-or cobalt-coordinated heteroatom doped carbons are promising alternatives for Pt-based cathode catalysts in polymer-electrolyte fuel cells. Currently, these catalysts are obtained at high temperatures. The reaction conditions complicate the selective and concentrated formation of metal-nitrogen active sites. Herein a mild procedure is introduced, which is conservative toward the carbon support and leads to active-site formation at low temperatures in a wet-chemical metal-coordination step. Active-site imprinted nitrogen doped carbons are synthesized via ionothermal carbonization employing Lewis-acidic Mg2+ salt. The obtained carbons with large tubular porosity and imprinted N-4 sites lead to very active catalysts with a half-wave potential (E-1/2) of up to 0.76 V versus RHE in acidic electrolyte after coordination with iron. The catalyst shows 4e-selectivity and exceptional stability with a half-wave potential shift of only 5 mV after 1000 cycles. The X-ray absorption fine structure as well as the X-ray absorption near edge structure profiles of the most active catalyst closely match that of iron(II) phthalocyanine, proving the formation of active and stable FeN4 sites at 80 degrees C. Metal-coordination with other transition metals reveals that Zn-Nx sites are inactive, while cobalt gives rise to a strong performance increase even at very low concentrations.
机译：铁或钴配位的杂原子掺杂碳是聚合物电解质燃料电池中基于Pt的阴极催化剂的有前途的替代品。目前，这些催化剂是在高温下获得的。反应条件使金属氮活性位的选择性和浓缩形成复杂化。在此引入了温和的程序，该程序对于碳载体是保守的，并且导致在低温下在湿化学金属配位步骤中形成活性位。通过使用路易斯酸性Mg2 +盐的离子热碳化合成活性位印氮掺杂碳。与铁配位后，在酸性电解液中，所获得的碳具有大的管状孔隙度并带有N-4印迹位点，从而产生了非常活跃的催化剂，其相对于RHE的半波电势（E-1 / 2）高达0.76V。该催化剂表现出4e选择性和出色的稳定性，在1000次循环后半波电势漂移仅为5 mV。活性最高的催化剂的X射线吸收精细结构以及靠近边缘结构的X射线吸收轮廓与酞菁铁（II）的紧密匹配，从而证明在80℃时形成了稳定的活性FeN4位。与其他过渡金属的配位揭示了Zn-Nx位不活泼，而钴即使在非常低的浓度下也能显着提高性能。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号