纳米多级孔Ti-SiO2/Ni-Mo-Co复合电极的制备及电解析氢协同增强机制研究

Water electrolysis is an important technique for hydrogen production. However, the electrode materials in water electrolysis have the disadvantages of high cost, small specific surface, low electrocatalytic activity and so on, which hinder the development of electrolyzing water for hydrogen evolution. This project is aim at the preparation of nano hierarchically porous Ti-SiO2/Ni-Mo composite electrode by using the method of composite electrodeposition. With this purpose, nano hierarchically porous Ti-SiO2 particles with high surface area were prepared by in-situ synthesis method, the nano hierarchically porous Ti-SiO2/Ni-Mo composite electrodes with high surface area, high electrocatalytic activity and low cost were prepared by using nano hierarchically porous Ti-SiO2 particles as composite particles. The dynamics and thermodynamic parameters of electrocatalytic hydrogen evolution on the nano hierarchically porous Ti-SiO2/Ni-Mo composite electrodes were obtained by electrochemistry technologies, and the dynamic process and reaction mechanism of electrolysis hydrogen evolution on the nano hierarchically porous composite electrodes were discussed, and then the synergistic enhancement mechanism of electrolysis for hydrogen evolution were revealed. The achievement would provide theoretic and technical support for water electrolysis with low energy, promote the development of the water electrolysis technique for hydrogen production.

电解水是大规模制氢的重要途径，但该技术存在的最大问题是电能消耗过大，其主要原因是电解电极的析氢过电位过高，因此研究低析氢过电位、高电催化活性的析氢电极对实现工业化廉价制氢具有重要的意义。针对这一问题，本项目提出先以原位合成法制备大比表面的纳米多级孔Ti-SiO2颗粒，再以Ti-SiO2颗粒为复合粒子，采用复合电沉积的方法，并对主要工艺条件进行优化，最终获得比表面积大、电催化析氢活性强以及成本较低的纳米多级孔Ti-SiO2/Ni-Mo-Co复合析氢电极。本项目创新地设计出构造纳米多级孔复合析氢电极的新思路，并结合多种电化学研究技术，获取复合电极电催化析氢过程中的动力学和热力学参数，探讨相关动力学过程以及反应机理，揭示纳米多级孔复合电极的电催化析氢协同增强机制，为实现低能耗、高效率电解水制氢提供技术支持和理论指导。

氢能是一种可再生的清洁能源，具有资源丰富、易储存等许多突出的优点。电解水是大规模制氢的重要途径，为了降低阴极过电位以节约能耗，研究低析氢过电位、高催化活性的阴极材料具有重要的意义。本项目系统探讨了各种工艺参数对电沉积Ni-Mo-Co合金的成分和电催化析氢活性的影响，确定出在柠檬酸体系中电沉积Ni-Mo-Co合金的最佳配方和工艺参数，得到Ni的质量分数为35.10%，Mo的质量分数为50.15%，Co的质量分数为14.75%的光亮Ni-Mo-Co合金镀层。通过对不同组分的Ni-Mo-Co合金电极的电催化析氢性能进行比较，结果表明：随着合金镀层中Mo和Co含量的增加，合金电极的电催化析氢活性逐渐增大。采用原位合成法成功地制备出直径为200-500nm，比表面积达573 m2/g，孔体积为1.19 cm3/g，介孔孔径为3.2 nm的纳米多级孔Ti-SiO2颗粒。以该纳米颗粒为复合粒子，采用复合电沉积法，制备出纳米多级孔Ti-SiO2/Ni-Mo-Co复合析氢电极，研究结果表明：纳米多级孔Ti-SiO2/Ni-Mo-Co复合析氢电极的电催化析氢活性比Ni-Mo-Co合金电极要好，降低析氢过电位60mV。