質子交換膜燃料電池(PEMFC)是一種不錯的替代能源，因為其主要的產物為水。具有核-殼結構的奈米顆粒觸媒可以改善氧氣還原反應(ORR)活性和耐久性。TEM 分析核-殼結構的Pd@Pt3Co/C 證明Pt3Co 合金沉積在Pd 奈米顆粒上。Pd@Pt3Co/C 的ORR 活性優於其他觸媒(Pt/C、Pd/C 和Pd@Pt/C)。在穩定性測試中，顯示Pd@Pt3Co/C的半電位在20,000 圈循環後會先衰退，然後在接下來的10,000 圈循環後恢復。Pt/C、Pd/C、Pd@Pt/C 和Pd@Pt3Co/C 的PEMFC 最大功率密度分別為639.3、382.4、721.8 和854.0 mW cm-2，表明Pd@Pt3Co/C優於其他觸媒。經穩定性測試後，Pd@Pt3Co/C 的最大功率密度幾乎沒有明顯下降，證明Pd@Pt3Co/C 可以作為優異且耐用的觸媒。Pd@Pt3Co/C 可藉由Pt3Co 合金殼在Pd 核上的高利用率以及Pd 核與Pt3Co 合金殼之間的配體效應、晶格應變效應和協同作用，來提升氧氣還原反應的活性。
另一部份則是通過在ZIF-67 中共摻雜鐵和氮原子，並進行800°C之熱處理和酸洗處理， 最後可得到最高氧氣還原反應活性的Fe−N−Co@C-800-AL。另外，Fe−N−Co@C-800-AL 即使以線性掃描伏安法(LSV)進行30000 圈穩定性測試後，也沒有顯示出明顯的衰退。所製備的觸媒是由奈米顆粒(NPs) 隨機分佈在多芳烴碳上的多孔結構，其BET 比表面積為449.0 m2 g-1。XPS 證明Fe−N−Co@C-800-AL含有大量的pyridinic-N 和graphitic-N，可以顯著增強氧氣還原反應的活性。此外，XAS 顯示Co-Co 和Fe-Fe 的存在以及缺乏Co-Nx 部分，這意味著氧氣還原反應主要來自氮摻雜於碳且包覆過渡金屬奈米顆粒的結構上。這些發現表明Fe−N−Co@C-800-AL 具有多孔結構、高表面積和含氮官能基的存在，從而使其適合於氧氣還原反應。

The proton exchange membrane fuel cell (PEMFC) is a good source
of alternative energy because its main product is water. To increase the
catalytic activity and durability of the nanoparticles with the core-shell structure in the oxygen reduction reaction (ORR). TEM analysis confirms that the core-shell structure of Pd@Pt3Co/C comprises Pt3Co alloy that is deposited on Pd nanoparticles. The ORR activity of Pd@Pt3Co/C is better than that of other samples - Pt/C, Pd/C and Pd@Pt/C. The stability test of Pd@Pt3Co/C shows more decay after 20000 cycles and then recover during the next 10,000 cycles. The maximum power densities of Pd@Pt3Co/C is the highest than the others in the PEMFC. After the stability test, the maximum power density of Pd@Pt3Co/C shows almost no obviously decay, which confirms Pd@Pt3Co/C can act as the outstanding catalyst. The improved activity of Pd@Pt3Co/C is associated with the high utilization of Pt3Co shell on the Pd core, the ligand effect, the lattice strain effect and the synergic effect between Pd core and Pt3Co alloy shell.
Second work demonstrates Fe−N−Co@C-800-AL through co-doped iron and nitrogen atoms in a ZIF-67, followed by optimal pyrolysis at 800°C and the acid leaching process. Fe−N−Co@C-800-AL is highly active in an oxygen reduction reaction. In addition, Fe−N−Co@C-800-AL shows no obvious degradation even after potential cycling of half-cell measurement (30,000 cycles). The prepared material exhibits a porous structure composed of nanoparticles (NPs) that were randomly distributed
on poly−hydrocarbon structures with a BET surface area of 449.0 m2 g−1. XPS demonstrates that Fe−N−Co@C-800-AL contained large amounts of pyridinic nitrogen and graphitic nitrogen, which could significantly enhance the activity of the oxygen reduction reaction. Furthermore, XAS reveals the existence of Co−Co and Fe−Fe and a lack of Co−Nx moieties, which means an oxygen reduction reaction may occur on the microstructures of N-doped carbon with wrapped metal NPs (Co or Fe).
These findings reveal that Fe−N−Co@C-800-AL had a porous structure, high surface area, and presence of functional nitrogen, thereby making it suitable for oxygen reduction reaction.

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