Mousumi Garai, Jayaraman Balamurugan, Zakir Ullah, Manmatha Mahato, Geetha Valurouthu, Jawon Ha, Sujin Cha, Habib Ullah, Hyunjoon Yoo, Akash Deo, Yury Gogotsi, Sang Ouk Kim, Il‐Kwon Oh
ABSTRACT Durable, cost‐effective hydrogen evolution in acidic media requires electrocatalysts that can rival platinum in catalytic activity and stability. We report atomically engineered Ti 3 C 2 T x @C 2 N heterostructure exploiting robust Ti–N interfacial bonding and electronic coupling to deliver platinum‐like performance without noble metals. The hybrid catalyst exhibits ultralow overpotential of 42 mV at 10 mA cm −2 and Tafel slope of 36 mV dec −1 , approaching commercial Pt/C benchmarks. More importantly, it maintains stable operation over 550 h at 100 mA cm −2 in corrosive acidic medium, far surpassing Pt/C. Structural analyses and density functional theory reveal that Ti─N interface optimizes hydrogen adsorption free energy and lowers the kinetic barrier for O─H bond cleavage, while the porous C 2 N scaffold enhances charge transport and active site accessibility. This synergistic structural and electronic design establishes a generalizable strategy for robust heterostructures, advancing scalable platinum‐free electrocatalysts for next‐generation proton exchange membrane electrolyzers and other energy conversion technologies.