Bolzan Gustavo R, Abarca Gabriel, Gonçalves Wellington D G, Matos Carolina F, Santos Marcos J L, Dupont Jairton
Institute of Chemistry, Universidade Federal do Rio Grande do Sul-UFRGS, Av. Bento Gonçalves, 9500, CEP, 91501-970, Porto Alegre, RS, Brazil.
Universidade Federal do Pampa, Av. Pedro Anunciação 111, CEP, 96570-000, Caçapava do Sul, Brazil.
Chemistry. 2018 Jan 26;24(6):1365-1372. doi: 10.1002/chem.201704094. Epub 2017 Dec 19.
A synergistic effect resulting from the interaction of small (2.4-3.1 nm) naked Pt nanoparticles (NPs) imprinted on N-doped carbon supports is evidenced by structural, electronic and electrochemical characterization. The size and distribution of the sputtered Pt NPs are found to be related to the nature of the support because Pt NPs are preferentially located at N sites. In addition, Rutherford backscattering shows that a deeper penetration of the Pt NPs is obtained in the N-doped carbon support with larger pore diameters. The ligand effect of the N-doped carbon supports is found to occur by electron donation from N and N sites to the Pt NPs and the electron acceptor behavior of the C=N sites. The carbon matrix acquires a basic characteristic (electron-richer, metallic behavior) capable of interacting with metallic NPs akin to a bimetallic-like system. The imprinted Pt NPs are active catalysts for oxidation, although displaying poor catalytic activity for reduction reactions. The catalyst N-doped carbon supports play an important role in the overall catalytic process, rather than only acting as a simple active phase carrier.
通过结构、电子和电化学表征证明，负载在氮掺杂碳载体上的小尺寸（2.4 - 3.1 nm）裸铂纳米颗粒（NPs）之间的相互作用产生了协同效应。发现溅射的铂纳米颗粒的尺寸和分布与载体的性质有关，因为铂纳米颗粒优先位于氮位点。此外，卢瑟福背散射表明，在孔径较大的氮掺杂碳载体中，铂纳米颗粒的穿透更深。发现氮掺杂碳载体的配体效应是通过氮和氮位点向铂纳米颗粒的电子给予以及C=N位点的电子受体行为而发生的。碳基体获得了一种基本特性（富电子、金属行为），能够与金属纳米颗粒相互作用，类似于双金属体系。印迹铂纳米颗粒是氧化反应的活性催化剂，尽管对还原反应显示出较差的催化活性。氮掺杂碳载体催化剂在整个催化过程中起着重要作用，而不仅仅是作为一个简单的活性相载体。
