Tailoring electrocatalytic CO₂ reduction pathways with femtosecond laser facilitated elemental doping of Cu foil

The electrochemical conversion of CO₂ into value-added chemicals presents an environmentally sustainable alternative to conventional fossil-derived processes, yet achieving high selectivity remains challenging due to competing reaction pathways. Here, we demonstrate precise tuning of CO₂ electroreduction pathways through femtosecond laser-driven surface doping of Cu with targeted metals, achieving Faradaic efficiencies of 58.9% for CO, 67.9% for formate, and 37.8% for ethylene. This spatially shaping laser technique enables nanoscale deposition of any metal (including Sb, Sn, Re, La, In, Co, Ni, Ag, and Pt) onto Cu foil, forming compositionally graded Cu-based bimetallic surfaces with controlled atomic ratios. Systematic electronic structure analysis reveals that secondary metals induce d-band center shifts spanning −0.21 to +0.78 eV, governing intermediate adsorption energetics-upward shifts strengthen *CO binding via enhanced back-donation, while downward shifts generally weaken adsorbate interactions. Through precise control of Cu/Sn and Cu/Sb atomic ratios, we manipulate electronic structures of CuSn and CuSb catalysts and consequently demonstrate continuous tuning of formate (19.0%–67.9%) and CO (18.8%–58.9%) selectivity. In-situ Raman spectroscopy and valence band X-ray photoelectron spectroscopy (XPS) elucidate dual modulation mechanisms. Sn enhances CO desorption by weakening *CO adsorption, whereas La promotes ethylene formation through optimized CO absorption and dimerization. The tunability of the reaction pathways aligns with metal-dependent stabilization of critical intermediates (CO and *OCHO). This work introduces a nanoscale-depth and trace-level multi-elemental loading strategy with tunable ratios on copper electrodes, enabling precise electronic structure manipulation of Cu-based electrocatalysts to mechanistically elucidate the correlation between surface electronic states and product selectivity, offering a roadmap to design and modulate Cu-based catalysts for selective CO₂-to-chemical conversion and beyond via low-cost laser processing techniques.