美国威斯康星大学麦迪逊分校Berry, John F.团队报道了由二钌络合物自发形成的N2可实现氨的电催化和需氧氧化。相关研究成果于2021年11月8日发表于国际一流学术期刊《自然—化学》。

在直接氨燃料电池（DAFC）中，氨的电化学转化为二氮是实现氮经济性的必要技术。以前用分子络合物催化该反应需要添加外源氧化试剂或施加大于氧还原反应（DAFC阴极过程）热力学电势的电势。

该文中，研究人员报道了一种稳定的金属-金属键合的二钌络合物，在环境条件下从氨中自发产生二氮。由此产生的还原二钌材料可以用氧再氧化，用于随后与氨的反应，表明其能够自发促进DAFC所需的两种半反应。与Fc0/+相比，在低至255mV的电位下，二钌络合物还充当氨电催化氧化为二氮的氧化还原介质，并在碱性条件下低于氧还原反应电位运行，从而实现与DAFC未来发展相关的热力学可行性。

附：英文原文

Title: Spontaneous N2 formation by a diruthenium complex enables electrocatalytic and aerobic oxidation of ammonia

Author: Trenerry, Michael J., Wallen, Christian M., Brown, Tristan R., Park, Sungho V., Berry, John F.

Issue&Volume: 2021-11-08

Abstract: The electrochemical conversion of ammonia to dinitrogen in a direct ammonia fuel cell (DAFC) is a necessary technology for the realization of a nitrogen economy. Previous efforts to catalyse this reaction with molecular complexes required the addition of exogenous oxidizing reagents or application of potentials greater than the thermodynamic potential for the oxygen reduction reaction—the cathodic process of a DAFC. We report a stable metal–metal bonded diruthenium complex that spontaneously produces dinitrogen from ammonia under ambient conditions. The resulting reduced diruthenium material can be reoxidized with oxygen for subsequent reactions with ammonia, demonstrating its ability to spontaneously promote both half-reactions necessary for a DAFC. The diruthenium complex also acts as a redox mediator for the electrocatalytic oxidation of ammonia to dinitrogen at potentials as low as 255mV versus Fc0/+ and operates below the oxygen reduction reaction potential in alkaline conditions, thus achieving a thermodynamic viability relevant for the future development of DAFCs.

DOI: 10.1038/s41557-021-00797-w

Source: https://www.nature.com/articles/s41557-021-00797-w