Lu Bingzhang, Liu Qiming, Nichols Forrest, Mercado Rene, Morris David, Li Ning, Zhang Peng, Gao Peng, Ping Yuan, Chen Shaowei
Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 950564, USA.
Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, Nova Scotia, Canada B3H 4R2.
Research (Wash D C). 2020 Nov 6;2020:9167829. doi: 10.34133/2020/9167829. eCollection 2020.
Oxygen reduction reaction (ORR) plays an important role in dictating the performance of various electrochemical energy technologies. As platinum nanoparticles have served as the catalysts of choice towards ORR, minimizing the cost of the catalysts by diminishing the platinum nanoparticle size has become a critical route to advancing the technological development. Herein, first-principle calculations show that carbon-supported Pt clusters represent the threshold domain size, and the ORR activity can be significantly improved by doping of adjacent cobalt atoms. This is confirmed experimentally, where platinum and cobalt are dispersed in nitrogen-doped carbon nanowires in varied forms, single atoms, few-atom clusters, and nanoparticles, depending on the initial feeds. The sample consisting primarily of Pt clusters doped with atomic Co species exhibits the best mass activity among the series, with a current density of 4.16 A mg at +0.85 V vs. RHE that is almost 50 times higher than that of commercial Pt/C.
氧还原反应（ORR）在决定各种电化学能源技术的性能方面起着重要作用。由于铂纳米颗粒一直是ORR的首选催化剂，通过减小铂纳米颗粒尺寸来降低催化剂成本已成为推动技术发展的关键途径。在此，第一性原理计算表明，碳载铂簇代表了阈值域尺寸，并且通过掺杂相邻的钴原子可以显著提高ORR活性。这在实验中得到了证实，其中铂和钴以不同形式分散在氮掺杂碳纳米线中，包括单原子、少原子簇和纳米颗粒，这取决于初始进料。主要由掺杂有原子钴物种的铂簇组成的样品在该系列中表现出最佳的质量活性，在相对于可逆氢电极（RHE）为+0.85 V时的电流密度为4.16 A mg，几乎是商业Pt/C的50倍。
