Reaction of Carbon with Nitric and Unified Mechanism for Oxidation Carbon Gasification

CTS-9523801这是一项碳和一氧化氮（形成氮和碳氧化物）之间反应的研究，包括对假设的表面氧络合物的检查，该络合物可能是所有碳氧化气化反应的统一机制的基础。在本研究的第一部分，使用电子显微镜和单晶石墨测量了碳和一氧化氮之间的反应速率，包括非催化反应和催化反应。对于非催化体系，测量包括氧和一氧化氮与碳的相对反应速率、活化能对温度的依赖、基面原子的提取动力学、水和一氧化碳的动力学效应以及表面氮的种类。对于催化反应，转换频率由石墨基面上的单层通道速率数据确定；催化剂选用过渡金属、碱金属和碱土。本研究的第二部分寻求更好地理解分子轨道理论提出的氧中间体；这个物种是统一机制的关键。用程序升温解吸法（TPD）研究了四种气体（氧气、一氧化氮、水和二氧化碳）下的四种石墨。在不同温度下中断TPD实验后，对石墨样品进行光谱分析（傅里叶变换红外，x射线光电子和碳-13核磁共振），以确定是否存在表面氧与一氧化碳脱附能之间的相关性。碳的“气化”是大量能源、化学和环境过程中的关键因素。本项目考察了碳气化反应家族中的一个反应（本系列中要研究的第四个反应），并试图将收集到的知识减少到该过程的统一机制。＊＊＊

ABSTRACT CTS-9523801 This is a study of the reaction between carbon and nitric oxide (forming nitrogen and carbon oxides), including an examination of a hypothetical surface oxygen complex which could be the basis for a unified mechanism for all oxidative gasification reactions of carbon. In the first part of this study, rates are measured for the reaction between carbon and nitric oxide using electron microscopy and single-crystal graphite for both uncatalyzed and catalyzed reactions. For the uncatalyzed system, measurements include the relative rates of reaction of oxygen and nitric oxide with carbon, the dependence of activation energy on temperature, the kinetics of abstraction of basal-plane atoms, kinetic effects of water and carbon monoxide, and surface nitrogen species. For catalyzed reactions, turnover frequency is determined from the monolayer channeling rate data on the basal plane of graphite; catalysts are selected from the transition metals, alkali metals, and alkaline earths. The second part of this study seeks better understanding of the oxygen intermediate suggested by molecular orbital theory; this species is the key to a unified mechanism. Four graphites with four gases (oxygen, nitric oxide, water, and carbon dioxide) are studied by temperature-programmed desorption (TPD). Spectroscopic analyses (Fourier-transform infrared, X-ray photoelectron, and carbon-13 nuclear magnetic resonance) are performed on graphite samples after interrupting TPD experiments at various temperatures to determine, if it exists, a correlation between surface oxygen species and carbon - monoxide desorption energies. The "gasification" of carbon is a key element in a large number of energy, chemical, and environmental processes. This, project examines one reaction (the fourth to be studied in this series) in the family of carbol gasification reactions and attempts to reduce the collected knowledge to a unified mechanism for the process. ***