Humidity sensitivity reducing of moisture swing adsorbents by hydrophobic carrier doping for CO2 direct air capture

•Fabrication method of solid adsorbent suitable for large-scale deployment was proposed.•Easy-to-operate method for improving the hydrophobicity of adsorbents was presented.•Moisture tolerance of adsorbents were enhanced after doping hydrophobic carrier.•CO2 adsorption performance of modified adsorbents at high humidity for DAC were excellent.•Moisture-swing regeneration ability and reusability were established for modified adsorbents. The application of quaternary ammonium-based moisture-swing adsorbent provides an effective strategy for direct air capture (DAC) with low energy consumption of regeneration. This study optimized a fabrication method of shaped adsorbents and a hydrophobicity regulation method by doping polyvinylidene difluoride (PVDF). Characterization of the shaped adsorbents showed a desirable surface area and pore structure. Experiments of CO2 adsorption revealed that the adsorbents exhibited excellent CO2 adsorption capacity (∼0.90 mmol/g) in relative humidity (RH) range of 20 ∼ 85% was enhanced by 160% of that before doping. Meanwhile, a high CO2 adsorption rate (with a half-time of 3.6 ∼ 3.82 min) at 84.7% RH was displayed. The optimal doping ratio of PVDF was found to be 25% (QAR-25% PVDF). It can effectively release CO2 with 100% RH, and heat assistance (