Particle Size Effects in the Catalytic Electroreduction of CO2 on Cu Nanoparticles

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• 作者：Rulle Reske ; Hemma Mistry ; Farzad Behafarid ; Beatriz Roldan Cuenya ; Peter Strasser
• 刊名：Journal of the American Chemical Society
• 出版年：2014
• 出版时间：May 14, 2014
• 年：2014
• 卷：136
• 期：19
• 页码：6978-6986
• 全文大小：471K
• 年卷期：v.136,no.19(May 14, 2014)
• ISSN：1520-5126

文摘

A study of particle size effects during the catalytic CO₂ electroreduction on size-controlled Cu nanoparticles (NPs) is presented. Cu NP catalysts in the 2鈥?5 nm mean size range were prepared, and their catalytic activity and selectivity during CO₂ electroreduction were analyzed and compared to a bulk Cu electrode. A dramatic increase in the catalytic activity and selectivity for H₂ and CO was observed with decreasing Cu particle size, in particular, for NPs below 5 nm. Hydrocarbon (methane and ethylene) selectivity was increasingly suppressed for nanoscale Cu surfaces. The size dependence of the surface atomic coordination of model spherical Cu particles was used to rationalize the experimental results. Changes in the population of low-coordinated surface sites and their stronger chemisorption were linked to surging H₂ and CO selectivities, higher catalytic activity, and smaller hydrocarbon selectivity. The presented activity鈥搒electivity鈥搒ize relations provide novel insights in the CO₂ electroreduction reaction on nanoscale surfaces. Our smallest nanoparticles (2 nm) enter the ab initio computationally accessible size regime, and therefore, the results obtained lend themselves well to density functional theory (DFT) evaluation and reaction mechanism verification.