Xiao Jing, Gao Min-Rui, Liu Subiao, Luo Jing-Li
Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada.
ACS Appl Mater Interfaces. 2020 Jul 15;12(28):31431-31438. doi: 10.1021/acsami.0c06891. Epub 2020 Jul 2.
Electrochemical reduction of CO to carbon-neutral fuels is a promising strategy for renewable energy conversion and storage. However, developing earth-abundant and cost-effective electrocatalysts with high catalytic activity and desirable selectivity for the target fuel is still challenging and imperative. Herein, hexagonal Zn nanoplates (H-Zn-NPs) enclosed by Zn(100) and Zn(002) facets were successfully synthesized and studied for their feasibility toward the CO reduction reaction (CORR). Compared with similarly sized Zn nanoparticles (S-Zn-NPs), the H-Zn-NPs exhibit remarkably enhanced current density, together with an improved CO faradaic efficiency (FE) of over 85% in a wide potential window, where a maximum FE of 94.2% is achieved. The enhancement in the CORR performance benefits from the substantial catalytically active sites introduced by the special architecture of H-Zn-NPs. Density functional theory calculations reveal that the exposed Zn(100) facets and edge sites on H-Zn-NPs are energetically favorable for CORR to CO, which directly result in an enhanced CORR performance. This study undoubtedly provides a straightforward approach to controlling the catalytic activity and selectivity of CORR through tuning the shape of Zn-based catalysts so as to maximize the percentage of exposed Zn(100) facets.
将CO电化学还原为碳中性燃料是可再生能源转换和存储的一种有前景的策略。然而，开发具有高催化活性和对目标燃料具有理想选择性的储量丰富且成本效益高的电催化剂仍然具有挑战性且势在必行。在此，成功合成了由Zn(100)和Zn(002)晶面包围的六边形Zn纳米片（H-Zn-NPs），并研究了其对CO还原反应（CORR）的可行性。与尺寸相似的Zn纳米颗粒（S-Zn-NPs）相比，H-Zn-NPs表现出显著增强的电流密度，并且在宽电位窗口内CO法拉第效率（FE）提高到85%以上，其中最大FE达到94.2%。CORR性能的提高得益于H-Zn-NPs特殊结构引入的大量催化活性位点。密度泛函理论计算表明，H-Zn-NPs上暴露的Zn(100)晶面和边缘位点在能量上有利于CORR生成CO，这直接导致CORR性能增强。这项研究无疑提供了一种直接的方法，通过调整Zn基催化剂的形状来控制CORR的催化活性和选择性，从而使暴露的Zn(100)晶面的比例最大化。
