Structure Sensitivity and Selectivity of Reactions on Metal Oxide Surfaces

这是一项对氧化物表面反应的结构要求和选择性的研究，目的是确定那些对设计新的催化氧化物材料重要的因素。研究了氧化锌和二氧化钛在单晶上的吸附和反应，确定了原型反应的结构灵敏度。研究的过程包括氧化锌锌极性面上的质子转移和亲核氧化，氧极性面上的亲电取代，以及棱镜面上双官能团的活化。为了阐明表面吸附键的性质及其对这两个基团的依赖性，定量地测定了多晶氧化物粉末上的相对表面吸附键强度；这也许可以解释在氧化锌上观察到的碳氢化合物和氧化反应的惊人选择性。最终，这项工作将导致设计和合成用作催化剂和传感器的新型氧化物材料的原理。

This is a study of the structural requirements and selectivity of reactions on oxide surfaces with the objective of determining those factors important for the design of new catalytic oxide materials. Adsorption and reaction on single crystals of zinc oxide and titania are studied to determine the structure sensitivity of archetypal reactions. Processes studied include proton transfer and nucleophilic oxidation on the zinc polar face of zinc oxide, electrophilic substitution on the oxygen polar face, and activation of difunctional species on the prism faces. Relative surface-adsorbate bond strengths on polycrystalline oxide powders are determined quantitatively in order to elucidate the nature of the surface-adsorbate bond and its dependence on both moieties; this may explain the surprising selectivities observed for hydrocarbon and oxygenate reactions on zinc oxide. Ultimately, this work should lead to principles for design and synthesis of novel oxide materials for use as catalysts and sensors.