Integration of Quantum Confinement and Alloy Effect to Modulate Electronic Properties of RhW Nanocrystals for Improved Catalytic Performance toward CO2 Hydrogenation

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• 作者：Wenbo Zhang ; Liangbing Wang ; Haoyu Liu ; Yiping Hao ; Hongliang Li ; Munir Ullah Khan ; Jie Zeng
• 刊名：Nano Letters
• 出版年：2017
• 出版时间：February 8, 2017
• 年：2017
• 卷：17
• 期：2
• 页码：788-793
• 全文大小：465K
• ISSN：1530-6992

文摘

The d-band center and surface negative charge density generally determine the adsorption and activation of CO₂, thus serving as important descriptors of the catalytic activity toward CO₂ hydrogenation. Herein, we engineered the d-band center and negative charge density of Rh-based catalysts by tuning their dimensions and introducing non-noble metals to form an alloy. During the hydrogenation of CO₂ into methanol, the catalytic activity of Rh₇₅W₂₅ nanosheets was 5.9, 4.0, and 1.7 times as high as that of Rh nanoparticles, Rh nanosheets, and Rh₇₃W₂₇ nanoparticles, respectively. Mechanistic studies reveal that the remarkable activity of Rh₇₅W₂₅ nanosheets is owing to the integration of quantum confinement and alloy effect. Specifically, the quantum confinement in one dimension shifts up the d-band center of Rh₇₅W₂₅ nanosheets, strengthening the adsorption of CO₂. Moreover, the alloy effect not only promotes the activation of CO₂ to form CO₂^δ− but also enhances the adsorption of intermediates to facilitate further hydrogenation of the intermediates into methanol.