One-step electrosynthesis of ethylene and ethanol from CO2 in an alkaline electrolyzer
One-step electrosynthesis of ethylene and ethanol from CO2 in an alkaline electrolyzer
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DOI：
10.1016/j.jpowsour.2015.09.124
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发表时间：
2016-01-01
影响因子：
9.2
通讯作者：
Kenis, Paul J. A.
中科院分区：
文献类型：
--
作者：
Ma, Sichao;Sadakiyo, Masaaki;Kenis, Paul J. A.
CO2的电还原具有储存否则浪费的间歇性可再生能源的潜力，同时减少CO2向大气中的排放。确定稳健和有效的电催化剂和相关的最佳操作条件以在高能量效率（低过电位）下生产烃仍然是一个挑战。在这项研究中，四个不同的形态和组成（表面氧化物的量）的铜纳米粒子催化剂的合成和其对CO2还原活性的特点是在碱性电解槽。使用具有大表面粗糙度的催化剂，在电流密度接近200 mA cm（-2）的情况下，将CO2电还原为乙烯和乙醇的综合法拉第效率（46%），在低得多的过电位下实现了10倍的性能提高（仅< 0.7 V）与之前的工作相比。与先前的工作相比，乙烯和乙醇的高生产水平可以主要归因于使用碱性电解质来改善动力学和抑制H-2的析出，以及在电解槽中应用覆盖有活性和粗糙Cu纳米颗粒的气体扩散电极。这些高性能水平和对铜基催化剂的基本理解使电化学还原过程更接近实际应用。(C)2015 Elsevier B. V.版权所有。
Electroreduction of CO2 has potential for storing otherwise wasted intermittent renewable energy, while reducing emission of CO2 into the atmosphere. Identifying robust and efficient electrocatalysts and associated optimum operating conditions to produce hydrocarbons at high energetic efficiency (low overpotential) remains a challenge. In this study, four Cu nanoparticle catalysts of different morphology and composition (amount of surface oxide) are synthesized and their activities towards CO2 reduction are characterized in an alkaline electrolyzer. Use of catalysts with large surface roughness results in a combined Faradaic efficiency (46%) for the electroreduction of CO2 to ethylene and ethanol in combination with current densities of similar to 200 mA cm(-2), a 10-fold increase in performance achieved at much lower overpotential (only < 0.7 V) compared to prior work. Compared to prior work, the high production levels of ethylene and ethanol can be attributed mainly to the use of alkaline electrolyte to improve kinetics and the suppressed evolution of H-2, as well as the application of gas diffusion electrodes covered with active and rough Cu nanoparticles in the electrolyzer. These high performance levels and the gained fundamental understanding on Cu-based catalysts bring electrochemical reduction processes such as presented here closer to practical application. (C) 2015 Elsevier B.V. All rights reserved.