Two-dimensional (2D) transition metal carbides and nitrides (MXenes) are a large family of earth-abundant materials with more than forty compositions synthesized since 2011, such as Ti2CTx, Nb2CTx, Ti3C2Tx, and Mo2Ti2C3Tx. MXenes have emerged as promising candidates for catalytic energy storage and conversion due to their electrochemically active surfaces combined with hydrophilicity, high electrical conductivity (up to 24,000 S/cm), and affinity to bond to molecules and nanomaterials to form hybrid structures. The ease of production of MXenes can overcome one of the major obstacles to the large-scale implementation of durable and efficient catalysts. This talk will discuss the control of MXene transition metals and their surfaces to tune their electrocatalytic behavior. Specifically, we will present the recently synthesized double-metal MXenes, such as W2TiC2Tx, Mo2Nb2C3Tx and surface-modified Mo2Ti2C3Tx and how we achieve low overpotential for hydron evolution reaction (as low as ~160 mV).