Grant: Research Tools and Instruments - Category 1 (<$150,000)

Over $1 trillion of revenue in the U.S. economy may be accounted for by catalyst technologies. Applications for these technologies range from new and innovative clothing fibres to medicine and alternative energy fuel cells. The underlying physics and chemistry that dictates how and why these processes occur, however, remains largely unknown for many catalytic systems. Now, there is a drive towards understanding catalytic systems on the smallest level, since studying the constituent pieces may lead to a more complete understanding of the bulk material. To do this, we require two laser systems: (1) a Nd:YAG laser as an ablation laser for a nanocluster molecular beam source and (2) an optical parametric oscillator (OPO) laser system as a tuneable probe laser system for interrogating nanocluster species. Laser ablation is the optimal method for generating small (< 20 atom) nanoclusters of catalytically relevant metals in molecular beam experiments. The laser ablation supersonic expansion process ensures efficient production of relatively cold nanoclusters, which facilitates surface adsorption (rather than decomposition) of ligands, and simplifies spectra through reducing the occurrence of hot-bands. As computational studies are tractable only for relatively small nanocluster sizes, the laser ablation production method is also optimal for our combined experimental / computational approach. As such, we are able to garner a better understanding of the chemistry and physics underpinning these systems. Owing to the fact that the energy level structure of nanoclusters varies dramatically with size and composition, spectroscopic and dynamic studies of these systems requires a widely-tuneable probe laser system. The wavelength extended OPO system provides a suitable spectral coverage at a resolution that will facilitate spectroscopic, dynamic and surface reactivity studies of nanocluster systems.