Thermodynamic Stability of Molybdenum Oxycarbides Formed from Orthorhombic Mo2C in Oxygen-Rich Environments
Thermodynamic Stability of Molybdenum Oxycarbides Formed from Orthorhombic Mo2C in Oxygen-Rich Environments
复制标题
富氧环境中正交 Mo2C 形成的碳氧化钼的热力学稳定性
DOI：
10.1021/acs.jpcc.7b11110
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发表时间：
2018
影响因子：
3.7
通讯作者：
["S. Likith
中科院分区：
文献类型：
--
作者：
["S. Likith
碳化钼（Mo2C）纳米颗粒和薄膜是特别适合用于催化快速热解（CFP）的催化剂，因为它们对脱氧有效并且可以催化通常在贵金属上发生的某些反应。在脱氧反应期间沉积的氧可改变碳化物结构，导致碳氧化物的形成，这可决定催化活性或选择性的变化。尽管出现了大量碳氧化物的光谱证据，但到目前为止，还没有关于其精确的原子结构或其相对于正交Mo2C的相对稳定性的报道。这些知识对于评估碳化钼（氧）对CFP的催化性能至关重要。在这篇文章中，我们使用密度泛函理论（DFT）计算（a）描述的热力学稳定性的表面和亚表面配置的氧和碳原子的钼终止表面的正交Mo2C和（B）确定碳氧化物的原子结构。
Molybdenum carbide (Mo2C) nanoparticles and thin films are particularly suitable catalysts for catalytic fast pyrolysis (CFP) as they are effective for deoxygenation and can catalyze certain reactions that typically occur on noble metals. Oxygen deposited during deoxygenation reactions may alter the carbide structure, leading to the formation of oxycarbides, which can determine changes in catalytic activity or selectivity. Despite emerging spectroscopic evidence of bulk oxycarbides, so far there have been no reports of their precise atomic structure or their relative stability with respect to orthorhombic Mo2C. This knowledge is essential for assessing the catalytic properties of molybdenum (oxy)carbides for CFP. In this article, we use density functional theory (DFT) calculations to (a) describe the thermodynamic stability of surface and subsurface configurations of oxygen and carbon atoms for a commonly studied Mo-terminated surface of orthorhombic Mo2C and (b) determine atomic structures for oxycarbide...