Gao Jiaojiao, Zhang Fei, Gan Wei, Gui Yawen, Qiu Huajun, Li Huanglong, Yuan Qunhui
Flexible Printed Electronics Technology Center and School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China.
Flexible Printed Electronics Technology Center and State Key Laboratory of Advanced Welding and Joining, and School of Sciences, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China.
ACS Appl Mater Interfaces. 2020 Oct 21;12(42):47667-47676. doi: 10.1021/acsami.0c15493. Epub 2020 Oct 8.
Development of bifunctional catalysts with low platinum (Pt) content for the ethanol oxidation reaction (EOR) and the oxygen reduction reaction (ORR) is highly desirable, yet challenging. Herein, we present structural engineering of a series of two-dimensional/three-dimensional (2D/3D) hierarchical N-doped graphene-supported nanosized PtCo alloys and Co clusters (PtCo@N-GNSs) via a hydrolysis-pyrolysis route. For the ORR, the optimal PtCo@N-GNS exhibits a high mass activity of 3.01 A mg, which is comparable to the best Pt-based catalyst obtained through sophisticated synthesis. It also possesses excellent stability with minor decay after 50 000 cyclic voltammograms (CV) cycles in acidic medium. For the EOR, PtCo@N-GNS achieves the highest mass-specific and area-specific activities of 1.96 A mg and 5.75 mA cm, respectively, among all of the reported EOR catalysts to date. The unique 2D/3D hierarchy, high Pt utilization, and valid encapsulation of nanosized PtCo/Co synergistically contribute to the robust ORR and EOR activities of the present PtCo@N-GNS. A direct ethanol fuel cell based on PtCo@N-GNS delivers a high open-circuit potential of 0.9 V, a stable power density of 10.5 mW cm, and an excellent rate performance, implying the feasibility of the bifunctional PtCo@N-GNS. This work offers a new strategy for designing an ultralow Pt loading yet highly active and durable catalyst for ethanol fuel cell application.
开发用于乙醇氧化反应（EOR）和氧还原反应（ORR）的低铂（Pt）含量双功能催化剂是非常必要的，但具有挑战性。在此，我们通过水解 - 热解路线展示了一系列二维/三维（2D/3D）分级N掺杂石墨烯负载的纳米级PtCo合金和Co簇（PtCo@N-GNSs）的结构工程。对于ORR，最佳的PtCo@N-GNS表现出3.01 A mg的高质量活性，这与通过复杂合成获得的最佳Pt基催化剂相当。在酸性介质中经过50000次循环伏安法（CV）循环后，它还具有出色的稳定性，衰减很小。对于EOR，在所有迄今为止报道的EOR催化剂中，PtCo@N-GNS分别实现了1.96 A mg和5.75 mA cm的最高质量比活性和面积比活性。独特的2D/3D层级结构、高Pt利用率以及纳米级PtCo/Co的有效封装协同促进了当前PtCo@N-GNS强大的ORR和EOR活性。基于PtCo@N-GNS的直接乙醇燃料电池具有0.9 V的高开路电位、10.5 mW cm的稳定功率密度和出色的速率性能，这意味着双功能PtCo@N-GNS的可行性。这项工作为设计用于乙醇燃料电池应用的超低Pt负载但高活性和耐用的催化剂提供了一种新策略。
