Electrochemically converting CO₂ to value-added multi-carbon (C₂₊) fuels and chemicals is a favorable way to achieve carbon neutrality. Herein, polyaniline/CuO nanosheets (PANI/CuO NSs) hybrid electrocatalysts are developed in order to achieve superior C₂₊ selectivity by imparting PANI functional component to the CuO NSs. The decorated PANI nanoparticles (NPs) can effectively stabilize the *CO intermediates and increase their coverage on the active Cu sites, which facilitates the C–C coupling to form multi-carbon products. Benefiting from the synergetic effect of PANI and CuO NSs, best Faradaic efficiency (FE) for C₂₊ product up to 66.4% at −1.6 V vs. reversible hydrogen electrode (RHE) in a H-cell measurement and 60.0% at 400 mA·cm⁻² in a flow cell measurement are demonstrated by PANI/CuO NSs-25 sample. More importantly, the C₂₊ selectivity keeps stable even in a continuous measurement time period of 92 h in H-cell measurement. The present study may provide more insights for designing efficient hybrid materials toward superior C₂₊ production from electrocatalytic CO₂ reduction.

Imposing phase engineering to porous materials is promising to realize outperforming electrocatalytic performances by taking advantages of the merits of porous nanoarchitecture and heterophase structure. In this work, amorphous/crystalline ruthenium oxide (RuO₂) porous particles with rationally regulated heterophases are successfully prepared by integrating the phase engineering into the porous material synthesis. The resultant defect-rich amorphous/crystalline RuO₂ porous particles exhibit excellent electrocatalytic performance toward the oxygen evolution reaction, achieving a low overpotential of 165 mV at a current density of 10 mA·cm⁻² and a high mass activity up to 133.8 mA·cm⁻² at a low overpotential of 200 mV. This work indicates that the synergistic effect of amorphous/crystalline heterophase and porous structural characteristics enables RuO₂ to trigger a superior electrocatalytic activity.