Abstract: Dispersed transition metal-nitrogen-doped carbon materials （M−N−C） exhibit remarkable potential for the electrochemical CO₂ reduction reaction （CO₂RR） due to their unique electronic structures and tunable coordination environments. However, the high geometrical and electronic symmetry of M-N₄ active sites often leads to reduced product selectivity, while conventional powdered catalysts generally suffer from low active site utilization, poor structural stabilityand mass transfer limitations, significantly restricting their practical application performance. To address these challenges, this study proposes a dual-effect synergistic regulation strategy: sulfur doping to reconstruct the coordination microenvironment of M-N₄ centers, breaking their inherent symmetry to enhance intrinsic catalytic activit, combined with a three-dimensional hierarchical porous monolithic structure design to optimize reactant/product mass transfer kinetics and improve charge transport efficiency. Using coal liquefaction pitch as carbon source, we fabricated a nickel-sulfur-nitrogen co-doped carbon foam monolithic catalyst via a polyurethane foam templating method and investigated its CO₂RR performance. The results demonstrate that the introduced sulfur atoms effectively modulate the electronic structure of Ni active centers, while the 3D interconnected framework facilitates greater exposure of active sites and accelerates both mass transport and charge conduction. This synergistic effect between the 3D architecture and S/N heteroatom-mediated electronic regulation significantly enhances CO₂RR performance. In 0.1 mol/L KHCO₃ electrolyte, the catalyst achieves 97.8% Faradaic efficiency for CO at −1.4 V vs. RHE with a current density of 57.8 mA/cm², while maintaining >90% CO selectivity across a broad potential window from −1.0 to −1.8 V vs. RHE, and stable operation for over 15 hours. This work establishes a novel structure-function cooperative regulation mechanism for designing high-performance monolithic electrocatalysts. Through dual-scale optimization combining “atomic-level coordination regulation” and “macroscopic structural design”, we provide new insights for developing efficient and stable monolithic CO₂RR electrocatalysts, while simultaneously expanding the high-value utilization pathways for low-rank carbon resources （e.g., liquefaction pitch）.