• • TPP-HCPs achieve a BET surface area of 548 m2 g-1 and CO2 uptake of 7.97 wt% at 1 bar and 298 K, providing abundant adsorption sites that enhance local CO2 concentration and improve catalytic turnover under industrially relevant currents.
• • CuO/TPP-HCPs deliver a total gas Faradaic efficiency exceeding 90% at ~500 mA cm-2 (-1.4 V vs. RHE), with 40.9% C2H4, 8.2% CH4, 31.9% CO, and 12.3% H2, demonstrating high selectivity for value-added products at high current density.
• • The composite maintains stable performance over 24 h in an H-cell, indicating robust structural integrity and resistance to deactivation, a critical requirement for continuous CO2 electrolysis.
• • The in-situ thermal conversion of Cu(NO3)2·3H2O at 135 °C within the TPP-HCP matrix enables uniform CuO nanoparticle dispersion, maximizing active site exposure and electron transfer, which collectively reduce overpotential and suppress hydrogen evolution.