The electrochemical CO₂ reduction reaction (CO₂RR) powered by renewable electricity is a promising route to close the carbon cycle, but it suffers from low product selectivity and high overpotential. Here we develop nitrogen and boron co-doped hollow carbon spheres (NB−CS) through the pyrolysis of a mixture comprising low-molecular-weight phenolic resols, melamine and boric acid. The optimized NB−CS catalyst presents high CO₂RR performance and achieves a CO Faradaic efficiency of 95.1% at a low overpotential of 310 mV, superior to carbon spheres doped with nitrogen or boron alone. Structural and electrochemical characterizations indicate that the efficient CO₂RR to CO over the NB−CS catalyst is likely ascribed to the unique graphitized architecture along with high conductivity, large surface area and high density of exposed N and B reactive sites. This work highlights opportunities to use cost-effective and readily available carbon nanomaterials as efficient CO₂RR catalysts.

中文翻译：

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用于二氧化碳电还原的氮和硼共掺杂碳球

由可再生电力驱动的电化学 CO ₂还原反应 (CO ₂ RR) 是关闭碳循环的一种很有前景的途径，但它存在产品选择性低和过电位高的问题。在这里，我们通过热解包含低分子量酚醛树脂、三聚氰胺和硼酸的混合物开发了氮和硼共掺杂的空心碳球（NB-CS）。优化后的 NB-CS 催化剂具有高 CO ₂ RR 性能，并在 310 mV 的低过电位下实现了 95.1% 的 CO 法拉第效率，优于单独掺杂氮或硼的碳球。结构和电化学表征表明，高效的 CO ₂NB-CS 催化剂上对 CO 的 RR 可能归因于独特的石墨化结构以及高导电性、大表面积和暴露的 N 和 B 反应位点的高密度。这项工作突出了使用具有成本效益且易于获得的碳纳米材料作为高效 CO ₂ RR 催化剂的机会。