Structural features, thermal stability and catalytic implication of Fe-Ni nanoparticles

We have carried out Monte Carlo and molecular dynamics simulations on FexNi1-x nanoparticles (NPs), and systematically studied their structural features and thermal stability. The required potential adopted the angular-dependent potential, which was newly obtained by us. It is found that when x < 0.375, the surface of FexNi1-x NPs is completely occupied by Ni atoms. When x > 0.375, the surface Fe concentration gradually increases with the increase of x. Inside the NPs, Fe atoms occupy the subsurface preferentially, and the Fe atom layer and Ni atom layer are arranged alternately. With the increase of x, the melting temperature of FexNi1-x nanoparticle first as-cends, then descends near x = 0.375, and then rises again near x = 0.875. In addition, the catalytic performance of FexNi1-x NPs in methane dry reforming was discussed. Considering the catalytic activity, carbon deposition resistance and sintering resistance, Fe0.375Ni0.625 NPs are the best choice.

Automated summary

We performed Monte Carlo and molecular dynamics simulations on FexNi1-x nanoparticles, investigating their structural features and thermal stability. The simulation results showed that the surface composition of the nanoparticles varied with x, and the arrangement of Fe and Ni atoms was alternate inside the nanoparticles. The melting temperature of the nanoparticles exhibited a non-monotonic dependence on x. Furthermore, we discussed the catalytic performance of the nanoparticles in methane dry reforming, and found that Fe0.375Ni0.625 nanoparticles demonstrated the best catalytic activity, carbon deposition resistance, and sintering resistance.