博士生孙吉平论文"Gradient pore engineering enables decoupled gas-liquid transport for highly-efficient CO2 electroreduction"被Science Bulletin接收发表
发布时间：2025-11-13
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The electrochemical CO2 reduction reaction (CO2RR) employing gas diffusion electrodes (GDEs) can reduce CO2 at the current densities required for commercialization (J> 200 mA cm-2). However, the competitive hydrogen evolution reactions (HER) are intensified under the high current densities, resulting in low Faraday efficiency (FE) of the products. Moreover, the occurrence of flooding and carbonate issue during electrolysis result in the clogging of the porous structure of the GDEs. Consequently, this hinders the mass transfer of CO2, and causes serious damage to the stability of the system. As the hydrophobic carbon support layer, the gas diffusion layer (GDL) is integral to the GDE design. The rational design of the GDL structure has been shown to synergistically manage gas (CO2) and liquid (H2O).[JW1] [JW2] In this study, the CO2RR performance was enhanced by designing the gradient pore structure of GDLs and regulating the transport of CO2 and H2O between electrodes. The multiscale structure of GDLs was precisely modified to effectively regulate the mass transfer, thereby preventing flooding and alleviating the carbonate issue. Combined with the commercial Ag catalysts, the optimized Ag-GDE exhibited a high CO selectivity (FE-CO>98.5%) while the FE-H₂<0.8%. The in-situ DEMS further confirmed the differences in mass transfer kinetics between CO2RR and HER exhibited by different GDLs. Furthermore, the visualization of H2O and CO2 distributions in GDLs was simulated in the presence of two-phase flows simultaneously by optimized LBM. This work offers an effective strategy of tailored GDL structures design and mass transfer management to promote efficient and stable CO2RR.