物理化学学报 >> 2021, Vol. 37 >> Issue (9): 2009087.doi: 10.3866/PKU.WHXB202009087

所属专题: 燃料电池

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中高温质子交换膜燃料电池催化剂研究进展

罗芳, 潘书媛, 杨泽惠()   

  • 收稿日期:2020-09-27 录用日期:2020-10-27 发布日期:2020-11-04
  • 通讯作者: 杨泽惠 E-mail:yeungzehui@gmail.com
  • 作者简介:杨泽惠,1987年生。2015年于日本九州大学应化系获博士学位。现任中国地质大学(武汉)副研究员。主要研究方向为燃料电池和电解水器件
  • 基金资助:
    国家自然科学基金(21703212)

Recent Progress on Electrocatalyst for High-Temperature Polymer Exchange Membrane Fuel Cells

Fang Luo, Shuyuan Pan, Zehui Yang()   

  • Received:2020-09-27 Accepted:2020-10-27 Published:2020-11-04
  • Contact: Zehui Yang E-mail:yeungzehui@gmail.com
  • About author:Zehui Yang, Email: yeungzehui@gmail.com. Tel.: +86-18672374372
  • Supported by:
    the National Natural Science Foundation of China(21703212)

摘要:

中高温质子交换膜燃料电池作为一种新型能量转换装置,具有环境友好、能量转换效率高、氢气纯度要求低等特点。催化剂作为电化学反应的核心,其性能极大影响着燃料电池的整体工作效率,目前针对中高温燃料电池催化剂的研究主要集中在电化学反应动力学较慢的阴极氧还原催化剂。磷酸掺杂的聚苯并咪唑(PA-PBI)为常用的高温质子交换膜,由于磷酸与PBI的结合力差,在长时间运行过程中磷酸容易渗透到催化剂层,造成磷酸在铂基催化剂表面的强吸附导致催化剂中毒的问题,并且氧分子在磷酸中溶解度低。基于以上问题,本文综述了铂基催化剂、非铂催化剂和非金属催化剂在中高温质子交换膜燃料电池中的应用现状,重点阐述了表面修饰、合金化、载体效应等策略对催化剂在磷酸电解液中的氧还原反应动力学的影响。最后针对目前中高温质子交换燃料电池催化剂发展方向进行了探讨和展望。

关键词: 中高温质子交换膜燃料电池, 磷酸中毒, 氧溶解度, 铂基催化剂, 非铂催化剂, 非金属催化剂

Abstract:

High-temperature polymer exchange membrane fuel cells (HT-PEMFCs), promising and sustainable energy conversion devices, have received considerable attention ascribed to their high energy conversion efficiency and zero emission. Different from the traditional Nafion PEMFCs, the working temperature ranks from 120 to 250 ℃ for HT-PEMFCs; as a result, HT-PEFMCs show impressive merits, such as theoretically higher kinetics, simple water/heat management and better tolerance toward impurities in hydrogen fuel; especially the elimination of flooding issue in fuel cells. Moreover, the working temperature matches well with the temperature for hydrogen generation from methanol reforming revealing that the generated heat from HT-PEMFCs can be utilized for methanol reforming to generate hydrogen; in this case, hydrogen tank can be replaced by methanol reforming system for HT-PEMFCs leading to a higher safety. Similar to traditional Nafion PEMFCs, polymer electrolyte membrane (PEM) associated with two electrodes representing for anode and cathode compose the membrane electrode assembly (MEA). Electrocatalyst as heart of HT-PEMFCs significantly affects the output of fuel cells, especially the cathodic electrocatalyst since the oxygen reduction reaction (ORR) kinetics is substantially sluggish than hydrogen oxidation reaction (HOR). Phosphoric acid doped polybenzimidazole (PA-PBI) is the state-of-the-art PEM for HT-PEMFCs; while, due to the low interaction between PA and PBI, PA leaching to the catalyst layer is normally observed during the long-term operation resulting in blocking of active sites to reduce three-phase boundary (TPB); besides, oxygen dissolution/diffusion in PA is much lower compared to Nafion, thereby, lower fuel cell performance is customarily recorded than Nafion PEMFCs. Thus, construction of high-performance ORR electrocatalyst with exceptional tolerance toward phosphate and increasing of oxygen concentration at TPB are highly desirable to realize the commercialization of HT-PEMFCs. Additionally, the stability of electrocatalyst should be significantly considered because the coalescence of platinum (Pt) nanoparticles as well as carbon corrosion is accelerated at high working temperature. In this review, we have summarized the recently reported Pt, non-Pt and meta-free electrocatalysts in HT-PEMFCs application. Surficial modification, alloying effect as well as substrate effect have been invited to construct high-performance Pt electrocatalyst in phosphoric acid electrolyte since the adsorption of phosphate on Pt is alleviated by surface coating and modulation of electronic configuration of Pt. Due to the comparably lower interaction with phosphate than Pt and considerable catalytic activity toward ORR, non-Pt and metal-free electrocatalyst have also been systematically investigated as HT-PEMFCs cathodic electrocatalyst. Finally, the perspectives and challenges in HT-PEMFCs have been discussed.

Key words: High-temperature polymer exchange membrane fuel cell, Phosphoric acid poisoning, O2 dissolution, Pt electrocatalyst, Non-Pt electrocatalyst, Metal-free electrocatalyst

MSC2000: 

  • O646