Mani Prabu, Sheelam Anjaiah, Das Shubhajit, Wang Guanxiong, Ramani Vijay K, Ramanujam Kothandaraman, Pati Swapan K, Mandal Sukhendu
School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Thiruvananthapuram, Kerala 695551, India.
Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India.
ACS Omega. 2018 Apr 4;3(4):3830-3834. doi: 10.1021/acsomega.8b00088. eCollection 2018 Apr 30.
Lack of control over the structure and electrically nonconductive properties of coordination polymers (CPs) creates a major hindrance to designing an active electrocatalyst for oxygen reduction reaction (ORR). Here, we report a new semiconductive and low-optical band gap CP structure [{Co(μ-OH)(BTB)(BPE)}{CoN(CH)}], , that exhibits high-performance ORR in alkaline medium. The electrical conductivity of compound was measured using impedance spectroscopy and found to be 5 × 10 S cm. The Ketjenblack EC-600JD carbon used as a support for all the electrochemical methods such as cyclic voltammetry, rotating disk electrode, rotating ring-disk electrode and Koutecký-Levich analysis. The as-synthesized Co-based catalyst has the ability to reduce O to HO by a nearly four-electron process. The crystal structure of shows that the trimeric unit {Co(μ-OH)(COO)N} and monomeric unit {Co(COO)(NCH)} are linked with BTB and BPE linkers to form a three-dimensional structure. Theoretical calculations predict that the monomeric center acts as an active catalytic site for ORR. This could be due to the efficient overlap of highest occupied molecular orbital-lowest unoccupied molecular orbital between monomer and O molecule. This CP, , shows facile 3.6-electron ORR, and it is inexpensive compared with widely used Pt catalysts. Therefore, this CP can be used as a promising cathode material for fuel cells in terms of efficiency and cost effectiveness.
对配位聚合物（CPs）的结构和非导电性能缺乏控制，给设计用于氧还原反应（ORR）的活性电催化剂带来了重大障碍。在此，我们报告一种新的半导体且低光学带隙的CP结构[{Co(μ-OH)(BTB)(BPE)}{CoN(CH)}]，其在碱性介质中表现出高性能的ORR。使用阻抗谱测量了化合物的电导率，发现其为5×10 S cm。科琴黑EC-600JD碳用作所有电化学方法（如循环伏安法、旋转圆盘电极、旋转环盘电极和科捷茨基-列维奇分析）的载体。合成的钴基催化剂能够通过近四电子过程将O还原为HO。的晶体结构表明，三聚体单元{Co(μ-OH)(COO)N}和单体单元{Co(COO)(NCH)}与BTB和BPE连接体相连形成三维结构。理论计算预测，单体中心作为ORR的活性催化位点。这可能是由于单体与O分子之间最高占据分子轨道-最低未占据分子轨道的有效重叠。这种CP显示出 facile 3.6电子ORR，并且与广泛使用的Pt催化剂相比价格低廉。因此，就效率和成本效益而言，这种CP可作为燃料电池有前景的阴极材料。
