直接甲醇燃料电池有序膜电极可控构筑及其内部多元多尺度传输耦合规律的研究

The ordered membrane electrode assembly (MEA) is a key component for the direct methanol fuel cell (DMFC). In ordered to greatly reduce the loading of Pt based catalysts and to promote the performance of the MEA, it is necessary to construct multicomponent transmission channels with maximized three-phase reaction interface, thus ensuring the effective coupling of the electrochemical reaction kinetics with multiple transportation. In this proposal, a new approach based on 3D printing method and electrohydrodynamic direct-writing technology is proposed for the controllable preparation of the MEA, which has ordered micron structural catalytic layer, nanostructure with rich Pt on surface and componential graded distribution. By studying the rule between the morphology of 3D printing orderly structural MEA, arrangement orientation, pore size and distribution, Nafion resin size and gradient distribution and the multicomponent mass transfer, exploring the effect of micron structures, nanostructure on the surface on both the utilization of the catalyst and the performance of MEA, elucidating the coupling rule between the electrochemical reaction rate and the multicomponent and multiscale mass transfer, the maximized three-phase reaction interface for fuel cell’s reaction, the effective transfer of molecules, protons and electrons, effective utilization of the catalyst, the reinforced compatibility of the interface and the performance of cell are realized. The present project will pave the way for the controllable construction of multiscale ordered MEA and speed up the practical application of the DMFC.

作为直接甲醇燃料电池(DMFC)核心部件的膜电极要实现催化剂用量的大幅减少和性能的显著提升，就必须构建多元传输通道并实现三相反应界面的最大化，实现电化学反应动力学与多元传输的有效耦合。本项目提出通过3D打印控制方法、结合电液动力直写技术可控构筑有序结构膜电极，实现膜电极催化层微米级有序结构表层的纳米结构化以及Nafion梯度分布的调控。重点研究3D打印有序膜电极催化层结构的形貌、排列取向、孔径大小及孔隙率、Nafion树脂尺寸及梯度分布等对膜电极内部多元多尺度传质的影响规律；探索微米级有序结构表层的纳米结构化对催化剂利用率、电池性能的影响，阐明膜电极内电化学反应动力学与内部多元多尺度传质的耦合规律，既实现三相反应界面的最大化，又可以促进分子、质子和电子的高效输运，显著提升催化剂利用率、界面相容性和电池性能，为多尺度有序结构膜电极的可控构筑奠定科学基础，推进DMFC实用化进程。

作为直接甲醇燃料电池(DMFC)核心部件的膜电极要实现催化剂用量的大幅减少和性能的显著提升，就必须构建多元传输通道并实现三相反应界面的最大化。本项目采用模板的方法，开发了二维Pt基催化剂并应用于高效纳米结构MEA的构筑，实现了催化剂用量的显著降低；为进一步降低MEA中Pt的用量，还创新发展了三维有序化纳米结构MEA的制备方法，研究了有序结构膜电极的构筑规律，探讨了阴极传质规律，阐明了有序结构膜电极的结构和电池性能之间的“构-效”关系，实现催化层三相反应界面的最大化，电荷转移电阻的最小化。同时，为提高DMFC的能量密度，研究了高浓度甲醇溶液供给的全被动式DMFC的阳极传质规律并优化了MEA的结构。进一步推进了DMFC实用化进程.