MXene基纳米材料在氧还原电催化中的应用

Application of MXene-based nanomaterials in electrocatalysis for oxygen reduction reaction

氧气还原反应(ORR)是燃料电池和金属-空气电池中的一个关键过程,反应动力学缓慢是制约其发展的瓶颈。MXene基纳米材料(包括MXenes复合材料)作为一种新型的二维层状材料,具有丰富的组成、高比表面积和化学稳定性、可调电子状态、大量暴露的活性位点等独特的结构特点,被认为是当前最有前途的一类ORR电催化剂或载体。开发高性能MXene基ORR催化剂为加速燃料电池和金属-空气电池阴极的缓慢ORR提供了新的途径。本文通过对近期相关文献进行分类总结,综述了MXene基ORR催化剂的设计原则,着重介绍了MXenes和MXenes复合材料在合成策略,组分、形态、结构与其电催化性能之间的构效关系,以及材料电催化反应机理等方面的最新研究进展。综合分析表明,通过构建MXene/过渡金属氧化物、MXene/过渡金属硫族化物、MXene/过渡金属氮化物、MXene/碳基材料、MXene/金属等MXenes复合材料,有望获得高活性、高稳定性的MXene基ORR催化剂。最后,本文提出该类催化剂目前在实际应用中面临的挑战,并指出MXene基纳米材料在电催化ORR方面的未来发展趋势。

Oxygen reduction reaction(ORR)is a key process in fuel cell and metal-air cells,and whose sluggish reaction kinetics is the bottleneck restricting its development.MXenebased materials(including MXenes composite materials)as a new type of two-dimensional(2D)layered structural materials have unique structural features such as rich composition,high specific surface area and high chemical stability,tunable electronic state,a large number of exposed active sites and so on,and they are considered to be the most promising ORR electrocatalysts or electrocatalyst supports.Therefore,the development of high-performance MXene-based ORR catalysts provides a new way to accelerate the sluggish ORR of fuel cells and/or metal-air battery cathodes.Herein,we classify and summarize the development of recent related literatures,reviewing of the design principles of MXene-based ORR catalysts,focusing on the latest research progress of MXenes and MXenes composite materials in terms of synthesis strategy,structure-activity relationship between components,morphology,structure and its electrocatalytic performance,as well as the electrocatalytic reaction mechanism of materials.Comprehensive analysis shows that MXenes composite materials,such as MXene/transition metal oxides,MXene/transition metal choridides,MXene/transition metal nitrides,MXene/carbon-based materials and MXene/metal,are expected to achieve high performance and high stability of MXene-based ORR catalysts.Finally,some challenges in the current application of MXene-based nanomaterials are presented,and the future prospects of the MXene-based ORR electrocatalysts are proposed.