...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Catalysis science & technology >In situ XAS study of the local structure and oxidation state evolution of palladium in a reduced graphene oxide supported Pd(ii) carbene complex during an undirected C-H acetoxylation reaction
【24h】

In situ XAS study of the local structure and oxidation state evolution of palladium in a reduced graphene oxide supported Pd(ii) carbene complex during an undirected C-H acetoxylation reaction

机译：原位xa的局部结构和学习氧化态钯的进化降低石墨烯氧化物Pd(2)碳烯的支持在无向复杂的碳氢键乙酰氧基化反应

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

In situ X-ray absorption spectroscopy (XAS) investigations have been performed to provide insights into the reaction mechanism of a palladium(ii) catalyzed undirected C-H acetoxylation reaction in the presence of an oxidant. A Pd(ii) N-heterocyclic carbene complex -stacked onto reduced graphene oxide (rGO) was used as the catalyst. The Pd speciation during the catalytic process was examined by XAS, which revealed a possible mechanism over the course of the reaction. Pd(ii) complexes in the as-synthesized catalyst first go through a gradual ligand substitution where chloride ions bound to Pd(ii) are replaced by other ligands with a mean bond distance to Pd matching Pd-C/N/O. Parallel to this the mean oxidation state of Pd increases indicating the formation of Pd(iv) species. At a later stage, a fraction of the Pd complexes start to slowly transform into Pd nanoclusters. The mean average oxidation state of Pd decreases to the initial state at the end of the experiment which means that comparable amounts of Pd(0) and Pd(iv) are present. These observations from heterogeneous catalysis are in good agreement with its homogeneous analog and they support a Pd(ii)-Pd(iv)-Pd(ii) reaction mechanism.
机译：原位x射线吸收光谱(xa)已进行调查洞察的反应机理钯(ii)催化无向碳氢键乙酰氧基化反应的存在氧化剂。堆放在降低石墨烯氧化物(rGO)用作催化剂。xa催化过程检查,发现的一个可能的机制的反应。第一次经历as-synthesized催化剂逐步配体取代氯离子绑定到Pd (ii)被其他配体取代平均债券距离Pd匹配Pd-C / N / O。Pd增加指示状态的形成Pd (iv)的物种。Pd复合物开始慢慢转变成Pd发光机制。Pd降低到初始状态这意味着类似的实验大量的Pd(0)和Pd (iv)。观察从多相催化与均匀模拟和好的协议他们支持一个Pd (ii) Pd (iv) Pd (ii)的反应机制。

著录项

相似文献

  • 外文文献
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