CAREER: In Situ Microscopy and Spectroscopy of Dynamic Behavior on Surfaces

英国普渡大学教授Jochen Lauterbach-9733821将使用基于成像椭圆偏振、红外振动和二阶非线性光学光谱的原位高分辨率方法跟踪催化表面的介观时空动力学。其主要目标是确定由于诸如表面非均质性或场地多样性等介观特征所引起的效应的非线性耦合而发生的周期性现象。潜在的协同效应将被用来构思基于定制表面非均质性的新催化剂。在类似汽车尾气催化的反应条件下，将在具有空间分辨组成差异的Rh-BaO-PT催化剂表面或在铂和铜箔上制备CeO2，同时研究CO和碳氢化合物的氧化和NOx的还原。脉冲红外激光加热将影响反应扩散体系的外强迫，使人们更好地理解共振强迫效应对CO氧化的影响，从而更好地理解非稳态反应器的运行。还将对反应、扩散和图案形成进行建模和模拟。第二个要研究的反应体系是空间分辨光诱导聚合，它可能导致新的成分调制聚合物薄膜。在紫外光引发下，丙烯醛、甲基丙烯醛和苯乙烯在不同的过渡金属表面(银、铜、铂)上的气相聚合将被对界面结构敏感的SSHG跟踪到微米厚度。同样，初始聚合步骤中的成键、电子和结构细节将在高真空条件下进行IR吸收或SFG研究，同时进行EMSI或SSHG。这项研究将反应-扩散现象的电子、分子、介观和宏观参数联系在一起，这些现象在催化、半导体制造、生物和聚合物涂层沉积等各个领域都很重要。在教育层面，Lauterbach教授将更新化学工程实验室课程，开设表面化学、催化、纳米力学、聚合物工程、全息术和光学工程实验，以及基于交互式电子媒体的新评估和教学方法。

Abstract - Lauterbach - 9733821 Prof. Jochen Lauterbach or Purdue University will follow mesoscopic spatio-temporal dynamics of catalytic surfaces with in-situ high-resolution methods based on imaging ellipsometry, IR vibrational, and second-order non-linear optical spectroscopy. The main objective is to identify periodic phenomena that occur because of nonlinear coupling of effects due to mesoscopic features such as surface heterogeneity or site diversity. The potentially synergistic effects will be exploited to conceive new catalysts based on tailored surface heterogeneity. CO and hydrocarbon oxidation simultaneously with NOx reduction will be studied on Rh-BaO-Pt catalyst surfaces microfabricated with spatially resolved compositional difference, or CeO2 on Pt and Cu foils, under reaction conditions resembling automobile exhaust catalysis. External forcing of reaction-diffusion systems will be effected by pulsed IR laser heating, leading to better understanding of resonant forcing effects on CO oxidation, and to unsteady state reactor operation in general. Modeling and simulation of reaction, diffusion, and pattern formation will also be carried out. A second reaction system to be investigated is spatially resolved photoinduced polymerization, which may lead to new compositionally modulated thin polymeric films. UV-initiated, mask-shadowed, gas-phase polymerization of acrolein, methacrolein, and styrene on various transition metal surfaces (Ag, Cu, Pt), will be followed up to a micron thickness by SSHG, which is sensitive to interfacial structure. Likewise, the bonding, electronic, and structural details during the initial polymerization steps will be studied under high vacuum conditions with IR absorption or SFG simultaneously with EMSI or SSHG. This research links electronic, molecular, mesoscopic and macroscopic parameters for reaction-diffusion phenomena that are important in various areas: catalysis, semiconductor manufacturing, biological and polymeric coating deposition. At the educa tional level, Prof. Lauterbach will renew the chemical engineering laboratory courses with experiments in surface chemistry, catalysis, nanoscale mechanics, polymer engineering, holography, and optical engineering, coupled with newer evaluation and teaching methods based on interactive electronic media.