...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Physical chemistry chemical physics: PCCP >Surface diffusion of gold nanoclusters on Ru(0001): effects of cluster size, surface defects and adsorbed oxygen atoms
【24h】

Surface diffusion of gold nanoclusters on Ru(0001): effects of cluster size, surface defects and adsorbed oxygen atoms

机译：金纳米团簇在Ru（0001）上的表面扩散：团簇大小，表面缺陷和吸附的氧原子的影响

获取原文
获取原文并翻译 | 示例
   

获取外文期刊封面封底 >>

       
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Understanding thermal behavior of metallic dusters on their solid supports is important for avoiding sintering and aggregation of the active supported metallic particles in heterogeneous catalysis. As a model system we have studied the diffusion of gold nano-clusters on modified Ru(0001) single crystal surfaces, employing surface density grating formation via a laser induced ablation technique. Surface modifications included damage induced by varying periods of Ne~+ ion sputtering at a collision energy of 2.8 keV and the effect of pre-adsorbed oxygen on the clean, defect free ruthenium surface. High density of surface damage, obtained at long sputter times, has led to enhanced diffusivity with lower onset temperature for diffusion. It is attributed to reduced cluster-surface commensurability which gives rise to smaller effective activation energy for diffusion. The diffusion of gold nano-clusters, 2 nm in size, was found to be insensitive to the oxygen surface concentration. The adsorbed oxygen acted as an "atomic layer lubricant", reducing friction between the cluster and the underlying surface. This has led to lower diffusivity onset temperatures (150 K) of the nano-clusters, with a stronger effect on smaller clusters.
机译：了解金属除尘器在其固体载体上的热行为对于避免多相催化中活性负载金属颗粒的烧结和聚集很重要。作为模型系统，我们研究了金纳米团簇在修饰的Ru（0001）单晶表面上的扩散，采用了通过激光诱导烧蚀技术形成表面密度的光栅。表面改性包括在2.8 keV的碰撞能量下，不同时间的Ne〜+离子溅射引起的损伤，以及预先吸附的氧气对干净，无缺陷的钌表面的影响。在长溅射时间获得的高表面损伤密度导致扩散率提高，扩散起始温度降低。这归因于降低的团簇表面可比性，这导致较小的有效扩散活化能。发现2纳米大小的金纳米团簇的扩散对氧表面浓度不敏感。吸附的氧气起“原子层润滑剂”的作用，减少了簇和下面的表面之间的摩擦。这导致较低的纳米团簇的扩散起始温度（150 K），对较小的团簇具有更强的影响。

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