CAREER: Investigation of Catalysis at Solid-Liquid Interfaces by Non-Linear Optical Spectroscopy

University Of South Carolina At Columbia, Columbia SC

Investigators

Abstract

The goal of the proposed research is to develop and use nonlinear optical techniques to study solid-liquid catalytic reactions important for fine chemical synthesis. The proposed research is a central part of an effort to study surface chemistry of heterogeneous fine chemicals and pharmaceuticals catalysis with modern in-situ spectroscopic techniques. The two approaches that will be used are sum frequency spectroscopy (SFS) and second harmonic generation (SHG). Both techniques are purely surface-selective, in that only the catalyst surface and the molecules adsorbed on it are detected. Two different types of experiments are planned. The first involves the study of model supported metal catalysts by total internal reflection (TIR) SFS and SHG. The second type of experiment will attempt to extend SHG (and eventually SFS) studies to catalyst particles in solution. Both methods will constitute the first application of nonlinear optical techniques to solid-liquid catalytic systems. Surface-enhanced Raman and infrared spectroscopic measurements will provide additional information regarding the state of catalyst surfaces. Parallel reaction rate measurements will be made in order to correlate surface in interface properties with catalytic rates and selectivity, and reaction mechanisms will be proposed. Fine chemicals and pharmaceuticals represent a rapidly expanding sector of the chemical industry. Heterogeneous catalysis shows promise for facilitating a smooth transition to more environmentally benign processing.