Pd Nanoparticles deposited on nitrogen-doped HOPG: New Insights into the Pd-catalyzed Oxygen Reduction Reaction
Pd Nanoparticles deposited on nitrogen-doped HOPG: New Insights into the Pd-catalyzed Oxygen Reduction Reaction
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DOI：
10.1016/j.electacta.2014.06.141
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发表时间：
2014-09-20
影响因子：
6.6
通讯作者：
Granozzi, Gaetano
中科院分区：
文献类型：
--
作者：
Ju, Wenbo;Favaro, Marco;Granozzi, Gaetano
表面科学和电化学的结合是一种有效的方法来接近的基本理解的电催化系统，特别是催化剂/载体组件。载体中的非本征化学缺陷会影响催化剂的性能，这是近年来电催化剂研究的热点。在这项工作中，氮官能团引入到最外层的高取向热解石墨（HOPG）的离子注入与束能量为100 eV。然后将钯纳米颗粒（Pd NP）电化学沉积到纯的和氮掺杂的HOPG（N-HOPG）上。在后一种情况下，观察到位于纳米颗粒和富氮表面之间的界面处的Pd 2+物种。结果表明，负载在N-HOPG上的Pd纳米粒子对氧还原反应具有与负载在纯HOPG上的Pd纳米粒子相同的电催化活性。然而，由于界面处Pd 2+的存在，可以加速Pd原子的溶解，N-HOPG上的Pd NPs对电位循环的稳定性强烈降低。该结果与文献中概述N掺杂优点的负载型Pt NP的结果相矛盾。(C)2014爱思唯尔有限公司版权所有。
The combination of surface science and electrochemistry is an effective method to approach a fundamental understanding of electrocatalytic systems, especially of the catalyst/support assemblies. Extrinsic chemical defects in the support can affect the performances and this topic is much investigated in recent electrocatalyst research. In this work, nitrogen functional groups are introduced into the outermost layers of highly oriented pyrolytic graphite (HOPG) by ion implantation with a beam energy of 100 eV. Palladium nanoparticies (Pd NPs) are then electrochemically deposited onto both pure and nitrogen doped HOPG (N-HOPG). Pd2+ species located at the interface between the NPs and the nitrogen-rich surface were observed in the latter case. The supported Pd NPs on N-HOPG show the same electrocatalytic activity for oxygen reduction reaction (ORR) as compared with those supported on pure HOPG. However, the stability of Pd NPs on N-HOPG towards potential cycling decreases strongly due to the existence of Pd2+ at the interface, which can accelerate the dissolution of Pd atoms. This result is contradictory to results on supported Pt NPs from the literature where the merit of the N-doping was outlined. (C) 2014 Elsevier Ltd. All rights reserved.