Native Defects in α-Mo2C: Insights from First-Principles Calculations
Native Defects in α-Mo2C: Insights from First-Principles Calculations
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DOI：
10.1021/jp507947b
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发表时间：
2014-10
影响因子：
3.7
通讯作者：
C. D. Oliveira;D. Salahub;H. A. Abreu;H. A. Duarte
中科院分区：
文献类型：
--
作者：
C. D. Oliveira;D. Salahub;H. A. Abreu;H. A. Duarte
碳化钼是一种很有前景的替代工业中使用的加氢催化剂的材料。它是使用不同来源的钼氧化物和碳合成的，例如七钼酸钼、氧化钼、葡萄糖、烷烃和甲苯。产生非化学计量材料，通常形成碳空位或钼空位，具体取决于合成路线。提出了一种计算空位形成亥姆霍兹自由能的方法，以固体中碳和钼原子能为参考。计算了不同温度下碳和钼空位的亥姆霍兹自由能。结果表明，在650 K时，存在9.6%的钼空位和10.2%的碳空位。对于低于610 K的温度，钼空位的浓度大于碳空位的浓度。计算了两种缺陷材料的电子定位函数（ELF），表明碳空位......
Molybdenum carbide is a promising material for replacing the hydrogenation catalysts used in industry. It has been synthesized using different sources of molybdenum oxides and carbon, such as molybdenum heptamolybdate, molybdenum oxides, glucose, alkanes, and toluene. Nonstoichiometric material is produced, normally forming carbon vacancies or molybdenum vacancies, depending on the synthetic route. An approach for calculating the Helmholtz free energy of vacancy formation has been proposed, taking as reference the carbon and molybdenum atomic energies in the solid. The Helmholtz free energy for the carbon and molybdenum vacancies for different temperatures has been calculated. The results show that at 650 K, 9.6% of molybdenum vacancies and 10.2% of carbon vacancies exist. For temperatures below 610 K, the concentration of molybdenum vacancies is larger than that of carbon vacancies. The electron localization function (ELF) has been calculated for both defective materials, showing that the carbon vacancy ...