Adsorbate Photochemical Dynamics

该研究项目由分析和表面化学项目支持，解决了分子在过渡金属表面吸附时光激发的详细动力学问题。利用纳秒可调脉冲激光系统，对吸附在Pt（111）表面的甲烷、氮和一氧化碳等吸附物分子进行光解吸、光破碎和光反应。角度分辨飞行时间质谱法用于检查物质解吸到气相，表面分析工具用于检查底物的变化。电子介导的光过程将通过使用碱吸附剂来降低金属衬底的功函数来检验。本研究获得的详细信息将有助于我们对多相催化和光辅助电子材料加工的进一步了解。光与吸附分子的相互作用形成了分析和表面化学计划支持的这项研究项目的主要焦点。激光引发的过程，如解吸，破碎和反应将通过检查过程的气相产物以及金属衬底的变化来探测。这些研究将有助于深入了解非均相催化系统的运作，以及激光辅助电子材料加工的机理信息。

This research project, supported in the Analytical and Surface Chemistry Program, addresses the question of the detailed dynamics of molecules photoexcited while adsorbed on transition metal surfaces. A nanosecond tunable pulsed laser system is used to initiate photodesorption, photofragmentation, and photoreaction of adsorbate molecules such as methane, nitrogen, and carbon monoxide adsorbed on the Pt(111) surface. Angle resolved time of flight mass spectrometry is used to examine species desorbing into the gas phase, and surface analytical tools are used to examine changes to the substrate. Electron mediated photoprocesses will be examined by the use of alkali adsorbates to lower the work function of the metallic substrate. Detailed information obtained in this research will be useful for our growing understanding of heterogeneous catalysis and photoassisted electronic materials processing. The interaction of light with adsorbed molecules forms the primary focus of this research project supported in the Analytical and Surface Chemistry Program. Laser initiated processes such as desorption, fragmentation, and reaction will be probed by examining the gas phase product of the process as well as changes to the metallic substrate. Insights into the operation of heterogeneous catalytic systems, as well as mechanistic information about laser assisted processing of electronic materials, should result from these studies.