Fundamental Investigation of Molybdenum Nitride and Carbide Catalysts: Minority Research Initiation Award

本提案旨在确定相组成、表面结构和化学计量对氮化钼和碳化物的催化性能的影响。一系列具有明确结构和化学计量学的薄膜被合成，评估了催化活性，并表征。薄膜是用离子束辅助沉积（IBAD）制备的，这种技术允许复合材料在控制结构和化学计量的情况下生长。吡啶的氢脱氮、环己烷的脱氢和环己烷的氢解分别用于测试活化C-N、C-H或C-C键的能力。主要表征是通过俄歇光谱、程序升温解吸和程序升温反应完成的。其他使用的技术包括x射线衍射、卢瑟福反向散射和电子显微镜。这项工作的目的是发展早期过渡金属氮化物和碳化物的结构，电子和催化性质之间的关系，从钼开始。它们具有各种商业过程的潜力，包括石油精炼、减少污染和将气体资源转化为液体燃料；在许多情况下，它们是稀有而昂贵的铂族金属的潜在替代品。这项工作的结果也可应用于摩擦学和电化学。

This proposal aims to determine the effects of phasic composition, surface structure, and stoichiometry on the catalytic properties of molybdenum nitrides and carbides. A series of thin films with well-defined structures anad stoichiometries are synthesized, evaluated for catalytic activity, and characterized. Thin films are prepared with ion-beam-assisted deposition (IBAD), a technique that permits growth of compound materials with control over structure and stoichiometry. Hydrodenitrogenation of pyridine, dehydrogenation of cyclohexane, and hydrogenolysis of cyclohexane are used to test for ability to activate C-N, C-H, or C-C bonds, respectively. Primary characterization is done with Auger spectroscopy, temperature-programmed desorption, and temperature-programmed reaction. Other techniques employed include X-ray diffraction, Rutherford back-scattering, and electron microscopy. The objective of this effort is to develop relationships between the structural, electronic, and catalytic properties of early transition-metal nitrides and carbides, starting with molybdenum. These have potential for a variety of commercial processes including petroleum refining, pollution abatement, and conversion of gaseous resources into liquid fuels; in many cases, they are prospective substitutes for rare and expensive platinum-group metals. The results of this work may also be applicable in tribology and electrochemistry.