MXenes and MBenes emerge from a large family of two-dimensional (2D) transition metal carbides, nitrides, carbonitrides, and borides and have drawn tremendous attention in recent years. They possess diverse elemental compositions, surface terminations and geometrical structures, and exhibit many fascinating physical and chemical properties. Specifically, these 2D compounds hold great promise for renewable energy applications owing to their superior electrical conductivity, high hydrophility, rich surface chemistry, and outstanding stability. In this perspective, we present a brief overview about the catalytic properties of MXenes, MBenes and MXene based heterostructures for typical electrochemical reactions. The roles of surface, edge and interface of these 2D nanostructures in energy conversion are highlighted from a theoretical point of view. Challenges and outlooks for future research are also outlined.

MXene和MBenes来自大量的二维（2D）过渡金属碳化物，氮化物，碳氮化物和硼化物，并引起了极大的关注。它们具有各种元素组成，表面终止和几何结构，并表现出许多令人着迷的物理和化学性质。具体而言，这些2D化合物具有优异的导电性，高亲水性，丰富的表面化学性质和出色的稳定性，因此在可再生能源应用方面具有广阔的前景。从这个角度出发，我们简要概述了MXene，MBenes和MXene基异质结构对典型电化学反应的催化性能。从理论的角度突出了这些二维纳米结构的表面，边缘和界面在能量转换中的作用。