Schafer D, Castegnaro M V, Gorgeski A, Rochet A, Briois V, Alves M C M, Morais J
Instituto de Física, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, 91501-970, Brazil.
Phys Chem Chem Phys. 2017 Apr 12;19(15):9974-9982. doi: 10.1039/c7cp00602k.
In situ X-ray absorption spectroscopy and mass spectrometry measurements were employed to simultaneously probe the atom specific short range order and reactivity of Pd and PtPd nanoparticles towards NO decomposition at 300 °C. The nanoparticles were synthesized by a well controlled, eco-friendly wet chemical reduction of metal salts and later supported on activated carbon. Particularly for the bimetallic PtPd samples, distinct atomic arrangements were achieved using a seeding growth method, which allowed producing a random nanoalloy, or nanoparticles with Pt- or Pd-rich core. X-ray photoelectron spectroscopy, transmission electron microscopy, and X-ray diffraction provided additional insights on their electronic, morphological and long range order structural properties. The results revealed that the higher the thermal induced atomic migration observed within the nanoparticles during thermal treatments, the least were their reactivity for NO abatement.
采用原位X射线吸收光谱和质谱测量方法，同时探测钯和铂钯纳米颗粒在300℃下对NO分解的原子特异性短程有序性和反应活性。通过对金属盐进行良好控制的、环境友好的湿化学还原法合成纳米颗粒，随后将其负载在活性炭上。特别是对于双金属PtPd样品，使用种子生长法实现了不同的原子排列，该方法可以制备随机纳米合金或具有富Pt或富Pd核的纳米颗粒。X射线光电子能谱、透射电子显微镜和X射线衍射对其电子、形态和长程有序结构性质提供了更多见解。结果表明，在热处理过程中纳米颗粒内观察到的热诱导原子迁移越高，其对NO减排的反应活性越低。
