Advances in CO2 Electroreduction over Hollow Fiber Gas Diffusion Electrodes

CO2 electroreduction (CO2RR) to high-value chemicals by renewable energy is a promising route for achieving carbon cycling. Traditional two-dimensional planar electrodes applied in CO2RR are faced with problems of high mass transfer resistance, carbonate precipitation, flooding, and complicated structures, seriously limiting their CO2RR efficiency and application. Three-dimensional hollow fiber gas diffusion electrodes (HFGDEs) are promising candidates due to their rich specific surface area, low mass transfer resistance, simplified component, and no flooding trouble, which are beneficial for achieving high current density as well as high CO2RR efficiency. In this review, we provide inspirations and positive paradigms for the rational design of HFGDE toward CO2RR by following part: 1. The mechanism of CO2RR. 2. The classification of the typical metal-based CO2RR catalysts. 3. The preparation process of HFGDEs. 4. Recent advanced HFGDE studies for CO2RR. 5. Challenges at this stage and future development of HFGDEs towards accelerating application of industrial CO2 reduction electrolyzers.