Characterization of Ni₃Sn intermetallic nanoparticles fabricated by thermal plasma process and catalytic properties...

The intermetallic compound Ni₃Sn has potential for application in hydrogen production as a catalyst. Herein, we synthesized Ni₃Sn nanoparticles through a thermal plasma process. We characterized the nanoparticles by synchrotron radiation X-ray diffraction and transmission electron microscopy analyses, and analyzed their catalytic properties for methanol decomposition in a temperature range of 513 to 793 K. The Ni₃Sn nanoparticles showed a higher selectivity to H₂ and CO than pure Ni nanoparticles, but a relatively lower catalytic activity for methanol decomposition compared to pure Ni nanoparticles. Density functional theory calculations revealed that the activation energy barrier for CO dissociation on Ni₃Sn (001) was 396 kJ/mol, which was higher than that for Ni (111). Moreover, the activation energy barrier for OH formation on Ni₃Sn (001) was 229 kJ/mol, which was significantly higher than that for Ni (111). This supported the experimental results and confirmed that the Ni₃Sn catalyst suppresses the formation of carbon and H₂O, compared to Ni catalyst.