Metal–Support Interaction Induced Electron Localization in Rationally Designed Metal Sites Anchored MXene Enables Boosted Electromagnetic Wave Attenuation

• Reconstruction of the electronic environment and optimization of electromagnetic attenuation are achieved by constructing a model of metal–support interaction regulated electron localization. • An excellent RLmin of −54 dB and an ultra-wide effective absorption bandwidth of 6.8 GHz are obtained in the 2D MXene system. • The microscopic pathway of 'local field-driven carrier migration → interfacial electron rearrangement → dipole polarization enhancement' has been elucidated. • This work provides critical insights into the relationship between electron localization and EMW dissipation, offering a pathway for electron localization engineering in functional materials.