Diffusion-Limited Formation of Nonequilibrium Intermetallic Nanophase for Selective Dehydrogenation.

Zhang, Guanghui; Ye, Chenliang; Liu, Wei; Zhang, Xiaoben; Su, Dangsheng; Yang, Xin; Chen, Johnny Zhu; Wu, Zhenwei et al. · Nano Lett · 2019

basic_science · Level V

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Abstract

Nonequilibrium intermetallic phases in the nanoscale were realized by diffusion-controlled solid-state transformation, forming SiO<sub>2</sub> supported NPs with Pd core and a CsCl type Pd<sub>1</sub>M<sub>1</sub> shell, where M is Sn or Sb. The core-shell geometry is identified from scanning transmission electron microscopy and infrared spectroscopy and the crystal structure is confirmed from in situ synchrotron X-ray diffraction and X-ray absorption spectroscopy. The highly symmetric Pd<sub>1</sub>M<sub>1</sub> intermetallic phase has not been reported previously and contains catalytic ensembles with high selectivity toward dehydrogenation of propane. The kinetically limited solid-state reaction is generally applicable to nanoparticle synthesis and could produce materials with desired structures and properties beyond conventional structural limits.