Abstract In this article, we present the preparation, characterization, and catalytic performance of bimetallic Co93Fe07 and Ni80Fe20 active mass loaded on synthetic nanodiamonds (SNDs) in the carbon dioxide (CO2) methanation. The pristine SNDs possessing a developed specific surface are thermally stable and inert to the reaction mixture of CO2 and dihydrogen. However, it is shown that 100% conversion of CO2 into methane can be reached at the lower temperature than that for a massive Co93Fe07 or Ni80Fe20 catalyst when 20 wt.% of the catalyst mass was loaded on the surface of SNDs. The catalytic activity of the prepared bimetallic/SNDs composites is estimated as the minimum temperature at the maximum conversion of CO2 at atmospheric pressure: it is 325 and 290 °C for Co93Fe07/SNDs and Ni80Fe20/SNDs, respectively. Thermal desorption studies showed that the methanation over Co-Fe/SNDs and Ni-Fe/SNDs catalysts run through the stage of CO2 dissociation into carbon and oxygen atoms and their subsequent interaction with hydrogen to form methane and water molecules. Scanning electron microscopy studies have shown that the presence of transition metal-rich sites on the surface of the carrier contributes to the improvement of efficiency of the Ni80Fe20 catalyst action.

中文翻译：

---

含有双金属 Ni(Co)-Fe 复合材料的合成纳米金刚石 (SND)：CO2 甲烷化反应的制备、表征和催化性能

摘要 在本文中，我们介绍了负载在合成纳米金刚石 (SND) 上的双金属 Co93Fe07 和 Ni80Fe20 活性物质在二氧化碳 (CO2) 甲烷化中的制备、表征和催化性能。具有发达的比表面的原始 SND 是热稳定的，并且对 CO2 和二氢的反应混合物呈惰性。然而，结果表明，当 20 wt.% 的催化剂质量负载在 SND 表面时，可以在比块状 Co93Fe07 或 Ni80Fe20 催化剂更低的温度下将 CO2 100% 转化为甲烷。制备的双金属/SNDs 复合材料的催化活性估计为大气压下 CO2 最大转化率的最低温度：Co93Fe07/SNDs 和 Ni80Fe20/SNDs 分别为 325 和 290°C。热解吸研究表明，Co-Fe/SNDs 和 Ni-Fe/SNDs 催化剂上的甲烷化经历了 CO2 分解成碳和氧原子以及随后与氢相互作用形成甲烷和水分子的阶段。扫描电子显微镜研究表明，载体表面富过渡金属位点的存在有助于提高 Ni80Fe20 催化剂作用的效率。