Catalytic hydrogen production and chemistry on transition metals.

摘要

Density Functional Theory (DFT) calculations serve as a useful tool to understand the atomic and molecular structure and properties, as well as chemical reactivity on well-defined solid surfaces. They help to elucidate the mechanisms of complex chemical transformations and also to identify new reaction intermediates. Recently, these calculations have also started to play an important role in the design of new and improved heterogeneous catalysts. However, to bridge the temperature and pressure gaps that exist between theoretical surface science and real world catalysis, a microkinetic model is needed.; First, the key concepts in DFT calculations and microkinetic modeling are introduced in this thesis. Then, the approach of combining DFT calculations with experiments and microkinetic modeling to gain a better understanding of surface chemistry and catalysis is applied to a number of reactions. Many of these reactions are related to the catalytic production and purification of hydrogen for fuel cells, for example, the decomposition of oxygenates like methanol, ethanol, ethylene glycol; the low temperature water gas shift reaction on supported gold catalysts and on iron promoted Pt and Pd catalysts; and the preferential oxidation of carbon monoxide in the presence of excess H 2. Finally, the use of DFT calculations for rational catalyst design is elucidated by identifying promising bimetallic catalysts that exhibit enhanced hydrogen uptake properties.