Dual-site synergy via interfacial engineering for enhanced CO2 electroreduction to methanol

Electrocatalytic CO 2 -to-methanol (MeOH) is hindered by the low efficiency of single-site catalysts, primarily due to insufficient local concentration of the key ⁎ CO intermediate. This work aims to construct a dual-site catalyst to synergistically boost ⁎ CO generation and its subsequent hydrogenation, thereby enhancing methanol production. Herein, a cooperative interface was designed by integrating single atoms Ni (SAs Ni) for CO 2 -to-CO conversion and amino-functionalized cobalt phthalocyanine (CoPc-NH 2 ) for methanol formation on N-doped carbon nanotubes ((SAs Ni + CoPc-NH 2 )/N-CNT). The dual-site catalyst achieves a remarkable methanol Faradaic efficiency (FE MeOH ) of 48.7% and a total current density of 45.6 mA cm −2 at −1.05 V vs. RHE, outperforming single-component CoPc-NH 2 /N-CNT (FE max  = 28.4%) and physically mixed SAs Ni/N-CNT + CoPc-NH 2 /N-CNT (FE max  = 30.6%) in an H-cell. A peak FE MeOH of 51.9% and a methanol partial current density of 103.8 mA cm −2 are achieved in a flow cell. When tested in a membrane electrode assembly (MEA) electrolyzer fed with simulated flue gas (10% CO 2 ), the catalyst delivers a current density of 500 mA cm −2 , while maintaining a FE MeOH of 67.1%. In situ attenuated total reflectance–surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) confirms the enhanced surface coverage of ⁎ CO and the emergence of the ⁎ CHO intermediate exclusively on the dual-site interface, revealing a synergistic mechanism wherein SAs Ni sites enrich the local ⁎ CO concentration and adjacent CoPc-NH 2 sites facilitate its selective hydrogenation to methanol. This work provides a catalyst design paradigm for efficient CO 2 -to-methanol conversion and offers fundamental insights into constructing cooperative interfaces for multistep electrocatalytic reactions. Download: Download high-res image (185KB) Download: Download full-size image