The electrochemical reduction reaction of CO₂ (CO₂eRR) to high value-added chemicals in an aqueous electrolyte usually faces challenges, including sluggish oxygen evolution at the anode and the competing reaction of hydrogen evolution at the cathode. A novel CoNi@NC composite with high saturation magnetization, prepared by facile pyrolysis, was used as the cathode and a Pt sheet as the anode in an ionic liquid (IL)-methanol electrolyte to conduct the CO₂eRR to produce CH₄ and CO, and oxidation of methanol to generate methylal (dimethoxymethane, DMM). A magnetic CoNi alloy nanomaterial (CoNi@NC) with a nitrogen-doped carbon layer-coated structure was synthesized by a one-pot method. The system achieved an associative strategy for synchronous production of high-valued chemicals via two half-reactions at the cathode and anode, respectively. The optimal CoNi@NC composite exhibited efficient catalytic activity, obtaining an average of 54.5% faradaic efficiency (FE) for DMM within 48 h and 91.9% of momentary FE for CO and CH₄ at 24 h under lower energy consumption. The electrode catalyst and ionic liquid electrolyte also exhibited good recyclability and stability in the CO₂eRR. Mechanism studies indicated that magnetic CoNi alloy species served as adsorption and active sites for CO₂ conversion. In addition, the carbon layer coating enhanced the stability of the CoNi alloy, and N-doping introduced surface defects on the carbon layer, thereby promoting CO₂ adsorption and electrocatalytic activity. Density functional theory (DFT) calculations demonstrated that the magnetic CoNi (1 1 1) species was conducive to CO₂ adsorption and activation, exhibiting high selectivity for the CO₂eRR.

中文翻译：

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磁性 CoNi@N 掺杂碳复合材料用于 CO2 电化学还原为 CH4，与离子液体电解质中的甲醇氧化为甲基醛有关


CO₂ （CO₂eRR） 与水性电解质中的高附加值化学品的电化学还原反应通常面临挑战，包括阳极析氧缓慢和阴极析氢的竞争反应。在离子液体 （IL）-甲醇电解液中，以 Pt 片为阳极，以离子液体 （IL）-甲醇电解质为阳极，以 CO₂eRR 产生 CH₄ 和 CO，并氧化甲醇生成甲基醛（二甲氧基甲烷，DMM）。CoNi@NC采用一锅法合成了一种具有氮掺杂碳层涂层结构的磁性 CoNi 合金纳米材料 （CoNi@NC）。该系统实现了一种结合策略，分别通过阴极和阳极的两个半反应同步生产高价值化学品。最佳 CoNi@NC 复合材料表现出高效的催化活性，在较低能耗下，DMM 在 48 h 内平均获得 54.5% 的法拉第效率 （FE），在 24 h 内获得 CO 和 CH₄ 的瞬时 FE 的 91.9%。电极催化剂和离子液体电解质在 CO₂eRR 中也表现出良好的可回收性和稳定性。机理研究表明，磁性 CoNi 合金种类是 CO₂ 转化的吸附位点和活性位点。此外，碳层涂层增强了 CoNi 合金的稳定性，N 掺杂在碳层上引入了表面缺陷，从而促进了 CO₂ 的吸附和电催化活性。 密度泛函理论 （DFT） 计算表明，磁性 CoNi （1 1 1） 物质有利于 CO₂ 的吸附和活化，对 CO₂eRR 表现出高选择性。