Highly Active Au/δ-MoC and Cu/δ-MoC Catalysts for the Conversion of CO2: The Metal/C Ratio as a Key Factor Defining Activity, Selectivity, and Stability

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• 作者：Sergio Posada-Pérez ; Pedro J. Ramírez ; Jaime Evans ; Francesc Viñes ; Ping Liu ; Francesc Illas ; José A. Rodriguez
• 刊名：Journal of the American Chemical Society
• 出版年：2016
• 出版时间：July 6, 2016
• 年：2016
• 卷：138
• 期：26
• 页码：8269-8278
• 全文大小：647K
• 年卷期：0
• ISSN：1520-5126

文摘

The ever growing increase of CO₂ concentration in the atmosphere is one of the main causes of global warming. Thus, CO₂ activation and conversion toward valuable added compounds is a major scientific challenge. A new set of Au/δ-MoC and Cu/δ-MoC catalysts exhibits high activity, selectivity, and stability for the reduction of CO₂ to CO with some subsequent selective hydrogenation toward methanol. Sophisticated experiments under controlled conditions and calculations based on density functional theory have been used to study the unique behavior of these systems. A detailed comparison of the behavior of Au/β-Mo₂C and Au/δ-MoC catalysts provides evidence of the impact of the metal/carbon ratio in the carbide on the performance of the catalysts. The present results show that this ratio governs the chemical behavior of the carbide and the properties of the admetal, up to the point of being able to switch the rate and mechanism of the process for CO₂ conversion. A control of the metal/carbon ratio paves the road for an efficient reutilization of this environmental harmful greenhouse gas.