Characterization of Ni3Sn intermetallic nanoparticles fabricated by thermal plasma process and catalytic properties for methanol decomposition

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 H-2 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.