Precursor Disorder-Mediated Crystallinity Regulation of Cu ₂ P ₂ O ₇ for Optimized Cu ⁺ /Cu ⁰ Interfaces toward Highly Selective CO ₂ Electroreduction to C ₂₊ Products

Electrochemical CO 2 reduction reaction (CO 2 RR) to high-value C 2+ products is pivotal for carbon neutrality, yet the rational design of Cu-based electrocatalysts with efficient C–C coupling and optimized Cu + /Cu 0 active interfaces remains a formidable challenge. Herein, we propose a structural disorder engineering strategy to fabricate phosphorus-modified Cu-BTC-derived electrocatalysts with tailorable phase and crystallinity. By precisely regulating 2-hydroxyphosphonoacetic acid loading, disorder of precursors is tuned, inducing the evolution of calcined catalysts from CuO/amorphous species to monoclinic Cu 2 P 2 O 7 with gradient crystallinity. O-CuBTC-HPAA-3, featuring the lowest Cu 2 P 2 O 7 crystallinity, delivers superior CO 2 RR performance, with a peak C 2+ Faradaic efficiency of 79.2% at high current density, as well as good electrolysis stability. Comprehensive characterizations, in situ spectroscopy, and density functional theory (DFT) calculations confirm that the catalytic superiority of O-CuBTC-HPAA-3 is depending on dynamic reconstruction into an optimal Cu + /Cu 0 ratio with abundant interfacial boundaries under CO 2 RR conditions. Such structure accelerates the rate-determining *CO protonation to *CHO, stabilizes the key *COCHO intermediate, and enables low-energy-barrier asymmetric C–C coupling. DFT calculation further verifies that the 4Cu + /Cu 0 model features an upshifted Cu d-band center, lowering the C 2+ formation energy barrier and enhancing metal-intermediate interactions. This work establishes a new paradigm for advanced CO 2 RR catalyst design via precursor engineering, reinforcing the fundamental understanding of structure–function relationships governing C 2+ selectivity in CO 2 RR.