As the core component of the electrochemical reduction of CO₂ (ERC), alkaline anion-exchange membranes (AEMs) in a CO₂ electrolyzer can not only transport hydroxide ions as conductors, but also prevent fuel crossover between two electrodes and reduce fuel loss. However, the membrane is threatened by low conductivity and poor stability. In this paper, AEMs based on polymer composites of bacterial cellulose (BC)/poly (diallyl dimethyl ammonium chloride) (PDDA) are developed for use in ERC, via a proposed impregnation, chemical cross-linking and ion-exchange process. The effects of crosslinking conditions and different BC:PDDA mass ratio on the hydroxide-ion conductivity, water content, microscopic and macroscopic morphological structure, and stability of BC-PDDA-OH^- membrane are thoroughly evaluated. The hydroxide-ion conductivity, incorporating BC:PDDA = 1:0.5 mass ratio, remains at 28.5mS cm⁻¹ and 17.89 mS cm⁻¹ after the membrane soaking in 0.5 M KHCO₃ and 0.5 M KOH solution for 720 h, respectively. At an applied potential of −0.96V_RHE, the BC-PDDA-OH^- membrane exhibits the highest Faradaic efficiency of 50.84% for formate (FE_HCOO^-) in 0.5 M KHCO₃ electrolyte, and the FE_HCOO^- only attenuates by 8.85% after 20 h of continuous electrolysis. In comparison, the BC-PDDA-OH^- membrane in 0.5 M KOH electrolyte produced the FE_HCOO^- of 50.92% at an applied potential of −1.006V_RHE. The electrochemical performances of both systems are superior to that of commercial acidic Nafion117 and commercial alkaline A901 membranes, which prove the feasibility of BC membrane fabricated AEMs application in high performance of ERC.

作为CO ₂（ERC）电化学还原的核心成分，CO ₂电解槽中的碱性阴离子交换膜（AEM）不仅可以传输氢氧根离子作为导体，而且还可以防止两个电极之间的燃料交叉并减少燃料损失。但是，该膜受到电导率低和稳定性差的威胁。本文提出了一种基于细菌纤维素（BC）/聚二烯丙基二甲基氯化铵（PDDA）聚合物复合材料的AEM，该材料通过拟议的浸渍，化学交联和离子交换工艺开发用于ERC。交联条件和不同BC的作用：BC-PDDA-OH PDDA质量比在氢氧离子传导性，水含量，微观和宏观形态结构，和稳定性^-膜被彻底评估。膜分别在0.5 M KHCO ₃和0.5 M KOH溶液中浸泡720 h后，结合BC：PDDA = 1：0.5质量比的氢氧根离子电导率保持在28.5mS cm ^-1和17.89 mS cm ^-1。在-0.96V的外加电位_RHE中，BC-PDDA-OH ^-膜表现出50.84％对甲酸盐（FE最高法拉第效率_HCOO ^- ）在0.5M KHCO ₃电解质和FE _HCOO ^-由8.85％仅衰减连续电解20小时后。相比较而言，BC-PDDA-OH ^-膜在0.5M KOH电解质中产生的FE _HCOO^-在-1.006V _RHE的施加电势下为-50.92％。两种系统的电化学性能均优于商用酸性Nafion117和商用碱性A901膜，这证明了BC膜制备的AEM在高性能ERC中应用的可行性。