Facilely tailored electrocatalyst with high-efficiency and durability for carbon dioxide (CO₂) to carbon monoxide (CO) conversion is appealing but remains challenging. Herein, small nickel nanoparticles (about 19.4 nm) confined in nitrogen-doped carbon (Ni NPs@N–C) with narrow size distribution are successfully constructed via a facile one-step calcination strategy of Ni containing MOF compounds. By virtue of the protective N-doped graphitized carbon shell and the uniformly distributed fine Ni nanoparticles in a narrow range from 13 to 21 nm, the as-obtained Ni NPs@N–C can exclusively convert CO₂ into CO with excellent Faradaic efficiency (FE) of 96.8% at − 1.0 V (vs. RHE), as well as the superior long-term catalytic stability over 24 h. Moreover, a high current density of more than 200 mA cm⁻² with a stable CO FE of 92% can be achieved in a flow cell configuration. This work paves a new way for the facile and potentially scale preparation of small metal nanoparticles for efficient CO₂- to-CO conversion.

Graphic Abstract

中文翻译：

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窄尺寸分布的镍纳米颗粒限制在氮掺杂碳中，以有效地将CO 2还原为CO

具有针对二氧化碳（CO ₂）到一氧化碳（CO）转化的高效性和耐用性的量身定制的电催化剂虽然吸引人，但仍然具有挑战性。在此，通过一种简便的含Ni的MOF化合物一步煅烧策略，成功地构建了窄尺寸分布的氮掺杂碳（Ni NPs @ N–C）中小的镍纳米颗粒（约19.4 nm）。借助保护性的N掺杂石墨化碳壳和在13至21 nm的窄范围内均匀分布的细Ni纳米颗粒，如此获得的Ni NPs @ NC可以专门转化CO ₂在− 1.0 V（vs. RHE）下具有优良的法拉第效率（FE）为96.8％的二氧化碳，以及在24小时内出色的长期催化稳定性。此外，在流通池构造中，可以实现大于200 mA cm ^-2的高电流密度和92％的稳定CO FE。这项工作为方便且可能规模化地制备小型金属纳米颗粒铺平了新途径，以实现有效的CO ₂ -CO转化。

图形摘要