Song Jian, Lei Xue, Mu Jiali, Li Jingwei, Song Xiangen, Yan Li, Ding Yunjie
Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Small. 2023 Dec;19(52):e2304423. doi: 10.1002/smll.202304423. Epub 2023 Aug 30.
Heteroatom-doping is an effective method for modifying the geometric symmetry of metal-nitrogen-carbon (M-N-C) single-atom catalysts and thereby tuning the electronic structure. Up to now, most of the current reports have concentrated on introducing heteroatoms into the highly symmetrical M-N structure. The coordination-unsaturated M-N structure is more sterically favorable for the insertion of alien atoms to optimize the electronic structure. Herein, a Ni-N catalyst with out-of-plane coordinated chlorine (Cl) atoms (Ni-N Cl/C) is successfully constructed on chlorine-functionalized carbon supports (C-Cl) for an efficient carbon dioxide reduction reaction (CO RR). Density functional theory calculations demonstrate that the prepared Ni-N Cl/C catalyst exhibits a higher capability in balancing COOH* formation and CO* desorption. In addition, in situ Raman spectra confirm that the lower CO binding energy on the Ni-N Cl/C facilitates CO escape, leading to excellent CO RR performance. A high CO Faradaic efficiency (FE ) of more than 80% is achieved from -0.6 to -1.2 V versus reversible hydrogen electrode on the Ni-N Cl/C and it exhibits negligible FE and current declination over a 40-h stability test. Furthermore, a high turnover frequency (TOF) value of 15 808 h is obtained, which is more than ten times that of Ni-N /C (1476 h ) without coordinated Cl atoms.
杂原子掺杂是一种修饰金属 - 氮 - 碳（M - N - C）单原子催化剂几何对称性从而调节电子结构的有效方法。到目前为止，大多数现有报道都集中在将杂原子引入高度对称的M - N结构中。配位不饱和的M - N结构在空间上更有利于外来原子的插入以优化电子结构。在此，在氯官能化的碳载体（C - Cl）上成功构建了具有面外配位氯（Cl）原子的Ni - N催化剂（Ni - N Cl/C）用于高效的二氧化碳还原反应（CO RR）。密度泛函理论计算表明，所制备的Ni - N Cl/C催化剂在平衡COOH形成和CO脱附方面具有更高的能力。此外，原位拉曼光谱证实，Ni - N Cl/C上较低的CO结合能有利于CO逸出，从而导致优异的CO RR性能。在Ni - N Cl/C上，相对于可逆氢电极，在-0.6至-1.2 V范围内实现了超过80%的高CO法拉第效率（FE），并且在40小时的稳定性测试中其FE和电流衰减可忽略不计。此外，获得了15808 h⁻¹的高周转频率（TOF）值，这是没有配位Cl原子的Ni - N /C（1476 h⁻¹）的十多倍。
