Crystal phase of metal nanocatalysts significantly affects their catalytic performance. Cu-based nanomaterials are unique electrocatalysts for CO2 reduction reaction (CO2RR) to produce high-value hydrocarbons. However, studies to date are limited to the conventional face-centered cubic (fcc) Cu. Here, we report a crystal phase-dependent catalytic behavior of Cu, after the successful synthesis of high-purity 4H Cu and heterophase 4H/fcc Cu using the 4H and 4H/fcc Au as templates, respectively. Remarkably, the obtained unconventional crystal structures of Cu exhibit enhanced overall activity and higher ethylene (C2H4) selectivity in CO2RR compared to the fcc Cu. Density functional theory cal-culations suggest that the 4H phase and 4H/fcc interface of Cu favor the C2H4 formation pathway compared to the fcc Cu, leading to the crystal phase-dependent C2H4 selectivity. This study demonstrates the importance of crystal phase engineering of metal nanocatalysts for electrocatalytic reactions, offering a new strategy to prepare novel catalysts with unconventional phases for various applications.

中文翻译：

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铜纳米材料电催化 CO2 还原中乙烯的选择性：依赖于晶相的研究

金属纳米催化剂的晶相显着影响其催化性能。铜基纳米材料是用于 CO2 还原反应 (CO2RR) 以生产高价值碳氢化合物的独特电催化剂。然而，迄今为止的研究仅限于传统的面心立方 (fcc) Cu。在这里，我们报告了在分别使用 4H 和 4H/fcc Au 作为模板成功合成高纯度 4H Cu 和异相 4H/fcc Cu 之后，Cu 的晶相依赖性催化行为。值得注意的是，与 fcc Cu 相比，获得的 Cu 的非常规晶体结构在 CO2RR 中表现出增强的整体活性和更高的乙烯 (C2H4) 选择性。密度泛函理论计算表明，与 fcc Cu 相比，Cu 的 4H 相和 4H/fcc 界面有利于 C2H4 形成途径，导致晶相依赖性 C2H4 选择性。这项研究证明了金属纳米催化剂晶相工程对电催化反应的重要性，为制备具有非常规相的新型催化剂提供了一种新策略，用于各种应用。