膜法酸碱两性电解水制氢基础研究

To meet the needs of sustainable energy development for national great strategy, this project focus on innovation of principle and technology for water electrolysis hydrogen production with lower energy consumption. We innovated an approach to generate hydrogen that membrane based-on acidic/alkaline amphoteric water electrolysis was proposed, in which membrane was fixed between acid and alkali half-cell for water electrolysis, the hydrogen evolution and oxygen electrode were separatively set in acidic and in alkaline aqueous solution. To avoid acid and alkali neutralization reaction, bipolar membrane was used to isolate acidic and alkaline aqueous solution. This proposal investigates the molecular interaction between water and membrane materials, influence of the applied electric field upon water splitting rate into hydrogen and hydroxyl ions, interpreting mechanism of ion migration through membranes, and designing bipolar membrane for acidic/alkaline amphoteric water electrolysis. Based on the principle that acidic environment is benefit for hydrogen evolution, and alkaline condition is good for oxygen generation in water electrolysis process, this novel approach reduces the thermodynamic potential for water electrolysis from 1.23V to 0.40V. Compared with water electrolysis in alkaline solution at cell voltage of 1.8V, hydrogen evolution rate increases by 4-6 times, greatly reducing energy consumption for water electrolysis hydrogen production. The achievement of this proposal will effectively promote the innovation of hydrogen production technology, generating fundamental knowledge for membrane based-on acidic/alkaline amphoteric water electrolysis.

面向能源可持续发展的国家重大战略需求，探索降低电解水制氢能耗的新原理与新方法。提出膜法酸碱两性电解水制氢过程，将双极膜置于析氢电极和析氧电极之间，氢气在酸性水溶液中产生，氧气在碱性环境析出。采用双极膜将酸性、碱性两个腔室隔离，避免发生酸碱中和反应。研究外加电场对膜内水分子解离的作用机理，进行高性能双极膜结构设计与制备，满足酸碱两性电解水制氢需求；解明酸碱溶液组成对电解过程的影响，探索析氢、析氧催化剂和电极制备，发展双极膜电解水制氢过程设计方法。由于酸性水溶液中析氢电势高，碱性水溶液内析氧电势低，电解水制氢的理论电位差从1.23伏降至0.40伏；双极膜将水分子解离为氢离子和氢氧根离子，电解过程不需要外加酸碱。与碱性水溶液电解水制氢相比，析氢速率提高4-6倍（对应1.8V槽电压），大幅度降低制氢能耗。研究成果有效推动新能源制氢技术发展，奠定膜法酸碱两性电解水制氢的理论基础。