Strain‐Controlled Pt Single‐Atom Catalysts on Crumpled MXene Supports for Highly Active Hydrogen Evolution

Strain engineering offers a powerful means to regulate the electronic structure and catalytic behavior of active metal sites, yet a general framework linking strain to electrocatalytic performance remains elusive beyond the conventional d‐band model. Here we report crumpled double‐transition‐metal MXene nanosheets (Mo 2 TiC 2 T x ) decorated with Pt single atoms, in which a tunable strain field is introduced through a physical diaphragm balloon method. The resulting cMo 2 TiC 2 T x ‐Pt SA catalyst exhibits outstanding alkaline hydrogen evolution performance, requiring overpotentials of only 24.9 and 75.5 mV to reach 10 and 50 mA cm −2 , respectively, together with a mass activity of 11 859 mA mgPt −1 , around 178‐fold higher than commercial Pt/C, a Tafel slope of 31.61 mV dec −1 and excellent durability. In situ spectroscopy and density functional theory calculations show that the ordered long‐range strain field around isolated Pt sites accelerates interfacial water activation while preserving near‐optimal H adsorption, thereby facilitating H 2 release. The resulting catalyst delivered a high current density of 3 A cm −2 at a low voltage of 1.98 V and maintained stable operation at 1000 mA cm −2 for over 500 h. These performance metrics underscore the potential of cMo 2 TiC 2 T x ‐Pt SA for industrial applications.