First-principle investigation of the interactions between PtxRu55−x (x = 0, 13, 42, 55) nanoparticles and [BMIM][PF6] ionic liquid

- Interaction between PtRu nanoparticle and [BMIM][PF6] is performed by DFT calculations.
- The structure of Pt13Ru42 nanoparticle is distorted induced by [BMIM][PF6].
- The d-band center show that catalytic activities of Pt13Ru42 and Ru55 are enhanced.
- Two C atoms of [BMIM][PF6] form the bond with Pt13Ru42 nanoparticles.

Density functional theory calculations have been performed to characterize the interactions between [BMIM][PF6] ionic liquid and icosahedral PtxRu55−x (x = 0, 13, 42, 55) nanoparticles. In Ru13Pt42-[BMIM][PF6], only one F atom of the anion form the bond with nanoparticle, resulting in the smallest interaction energy (−0.56 eV). While in Pt13Ru42-[BMIM][PF6], two F atoms of the anion together with two C atoms of cation form the bonds with nanoparticle, resulting in the biggest interaction energy (−10.65 eV). The interaction between [BMIM][PF6] and Pt13Ru42 is so strong that it induces a significant distortion in the original core-shell structure of Pt13Ru42. Moreover, after interacting with [BMIM][PF6], the Pt55, Pt13Ru42 and Ru55 nanoparticles become more stable based on the negative relaxation energy. The d-band centers of Pt13Ru42 and Ru55 shift from −1.90, −1.78 eV up to −1.78, −1.56 eV, suggesting that the catalytic activities of Pt13Ru42 and Ru55 are enhanced.