MXene is a variety of new two-dimensional (2D) materials with early transition metal carbides, nitrides, and carbonitrides. Quantum chemical studies have been carried out on the geometries, electronic structures, stability and catalytic properties of a non-noble metal single-atom catalyst (SAC) with single Co atom anchored on MXene materials of Mo₂CS₂. The Co adatom anchored on top of the Mo atom of this MXene is found to be rather stable, and this SAC is appropriate for CO oxidation. The charge transfers from the surface to the adsorbed CO and O₂ play a significant role in the activation of these molecules on Co₁/Mo₂CS₂. With this catalyst, the Eley-Rideal (ER), Langmuir-Hinshelwood (LH), and Termolecular Eley-Rideal (TER) mechanisms are explored for CO oxidation. We find that, while all the three mechanisms are feasible at low temperature, Co₁/Mo₂CS₂ possesses higher catalytic activity for CO oxidation through the TER mechanism that features an intriguing OC(OO)CO intermediate (IM) adsorbed on Co single atom. The calculated activation energy barriers of the rate-limiting step are 0.67 eV (TER), 0.78 eV (LH) and 0.88 eV (ER), respectively. The present study illustrates that it is promising to develop and design low-cost, non-noble metal SACs using MXene types of 2D materials.

MXene是具有早期过渡金属碳化物，氮化物和碳氮化物的各种新型二维（2D）材料。已经对具有单个Co原子锚定在Mo ₂ CS _2的MXene材料上的非贵金属单原子催化剂（SAC）的几何形状，电子结构，稳定性和催化性能进行了量子化学研究。发现锚固在该MXene的Mo原子的顶部上的Co原子非常稳定，并且该SAC适合于CO氧化。电荷从表面转移到吸附的CO和O ₂在这些分子在Co ₁ / Mo ₂ CS ₂上的活化中起重要作用。使用这种催化剂，探索了Eley-Rideal（ER），Langmuir-Hinshelwood（LH）和Termolecular Eley-Rideal（TER）机理来氧化CO。我们发现，虽然所有这三种机理在低温下都是可行的，但Co ₁ / Mo ₂ CS ₂通过TER机制具有对CO氧化的更高催化活性，该TER机制具有吸附在Co单体上的有趣的OC（OO）CO中间体（IM）。原子。限速步骤的计算活化能垒分别为0.67 eV（TER），0.78 eV（LH）和0.88 eV（ER）。本研究表明，使用MXene类型的2D材料开发和设计低成本，非贵金属SAC是有希望的。