Abstract Carbon monoxide (CO), as one of the major gaseous product in the oxy-fuel combustion boiler, is found to exert great influence on nitric oxide (NO)-char reactions. Unfortunately, the detailed mechanism of CO enhancement still remains obscure. In this work, starting from the armchair model with embedded nitrogen, we propose some updated mechanisms with details at the molecular level that can describe the role of CO through energetic and kinetic evaluations based on the combination of density functional theory (DFT), transition state theory (TST) and Chemkin calculations. The preferred pathways are identified with 54 intermediates and 68 transition states. The addition of CO to the surface carbyne site with C-down mode is the most favorable and triggers the low-temperature desorption of CO2 via C C bond dissociation due to its low barrier of approximately 40 kJ/mol. One important role of CO is to react with the surface oxygen atom in the species C(NO) to clean the surface. More specifically, the energy barrier for nitrogen exposure reduced from 311.8 kJ/mol to 243.4 kJ/mol if the aromatic armchair edge is clean, and further reduced to 211.8 kJ/mol with the existence of nearby carbine type site. In addition, N2 desorption, is sensitive to, and largely facilitated by, the presence of CO. The results are of great value to interpret various reported experimental phenomena, including but not limited to, the small effect of CO at high temperatures, the initial NO reduction temperature at char surface, and the important impact of CO on the reaction activation energy.

中文翻译：

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一氧化碳对 NO 和炭结合氮之间相互作用的最新影响：热力学和动力学联合研究

摘要 一氧化碳（CO）作为富氧燃烧锅炉中的主要气态产物之一，被发现对一氧化氮（NO）-炭反应有很大影响。不幸的是，CO 增强的详细机制仍然不清楚。在这项工作中，从嵌入氮的扶手椅模型开始，我们提出了一些更新的机制，在分子水平上提供细节，可以通过基于密度泛函理论 (DFT)、过渡态的能量和动力学评估来描述 CO2 的作用理论 (TST) 和 Chemkin 计算。首选途径由 54 个中间体和 68 个过渡态确定。以 C-down 模式将 CO 添加到表面碳炔位点是最有利的，并且由于其大约 40 kJ/mol 的低势垒，通过 CC 键解离触发 CO2 的低温解吸。CO 的一个重要作用是与物质 C(NO) 中的表面氧原子反应以清洁表面。更具体地说，如果芳香扶手椅边缘干净，氮暴露的能垒从 311.8 kJ/mol 降低到 243.4 kJ/mol，并且在附近存在卡宾型位点时进一步降低到 211.8 kJ/mol。此外，N2 解吸对 CO 的存在很敏感，并且很大程度上受 CO 的存在促进。结果对于解释各种报道的实验现象具有重要价值，包括但不限于 CO 在高温下的小影响，初始炭表面没有还原温度，