Kim Hee-Eun, Kwon Jaehoon, Lee Hyunjoo
Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology Daejeon 34141 South Korea
Chem Sci. 2022 May 4;13(23):6782-6795. doi: 10.1039/d2sc00541g. eCollection 2022 Jun 15.
Proton exchange membrane fuel cells (PEMFCs) produce electricity from H without carbon emission, and they are considered as environmentally benign energy conversion devices. Although PEMFCs are mature enough to find themselves in a few commercial automobiles such as Hyundai Nexo and Toyota Mirai, their durability should be enhanced, especially under transient conditions, and Pt use should be reduced significantly to expand their market. Herein, we introduce examples of how catalysts can contribute to enhancing the durability of PEMFCs while minimizing Pt use. Numerous electrocatalysts have been reported claiming superior activity in a half-cell setup, but they often fail to show the same enhancement in a single cell setup due to various transfer problems, impurity poisoning, This perspective focuses on catalysts tested in a membrane-electrode-assembly (MEA) setup. As examples to obtain durability under transient conditions, catalysts used in reversal-tolerant anodes (RTAs) and selective anodes are explained. RTAs can endure sudden H starvation, and selective anodes can operate properly when O is unexpectedly mixed with H in the anode. As examples with high durability in long-term operation, Pt-based nanoparticle catalysts encapsulated with carbon shells are explained. Interestingly, PtCo nanoparticles supported on Co-N-C or PtFe nanoparticles encapsulated with a carbon shell presented a superior cell performance in spite of <1/10 Pt use in an MEA setup. Non-Pt group metal (PGM) catalysts used in an MEA setup are also briefly explained. With these highly durable catalysts which can respond properly under transient conditions with minimum Pt use, PEMFC technology can bring about a more sustainable society.
质子交换膜燃料电池（PEMFC）通过氢气发电且无碳排放，被视为环境友好型能量转换装置。尽管PEMFC已足够成熟，应用于现代Nexo和丰田Mirai等少数商用汽车中，但其耐久性仍需提高，特别是在瞬态条件下，并且应大幅减少铂的使用以扩大市场。在此，我们介绍一些催化剂如何在减少铂使用的同时提高PEMFC耐久性的实例。已有许多电催化剂报道称在半电池装置中具有优异的活性，但由于各种传输问题、杂质中毒等，它们在单电池装置中往往无法表现出同样的性能提升。本观点聚焦于在膜电极组件（MEA）装置中测试的催化剂。作为在瞬态条件下获得耐久性的实例，解释了用于耐逆转阳极（RTA）和选择性阳极的催化剂。RTA能够承受突然的氢气饥饿，而选择性阳极在阳极中氧气意外与氢气混合时能正常运行。作为长期运行中具有高耐久性的实例，解释了用碳壳包裹的铂基纳米颗粒催化剂。有趣的是，负载在Co-N-C上的PtCo纳米颗粒或用碳壳包裹的PtFe纳米颗粒在MEA装置中尽管铂的用量不到1/10，但仍表现出优异的电池性能。还简要解释了在MEA装置中使用的非铂族金属（PGM）催化剂。有了这些能够在瞬态条件下以最少铂用量做出适当响应的高耐久性催化剂，PEMFC技术可以带来一个更可持续的社会。
