Theoretical insights into the interaction between RunPt13-n (n = 4, 7 and 9) clusters and [BMIM]+ based ionic liquids: Effect of anion

Abstract Density functional theory has been performed to systematically study the interactions between Ru n Pt 13-n (n = 4, 7 and 9) clusters and [BMIM] + based ionic liquids. Ionic liquids [BMIM][Br], [BMIM][BF 4 ], [BMIM][PF 6 ], [BMIM][CF 3 SO 3 ], and [BMIM][NTf 2 ] have different effects on the stability of Ru 7 Pt 6 . Ionic liquids with median size anions of PF 6 − and CF 3 SO 3 − can better improve the stability of Ru 7 Pt 6 than those with the small anions of Br − and BF 4 − and large anion of NTf 2 − . Based on negative relaxation energies, the stabilities of Ru 4 Pt 9 , Ru 7 Pt 6 , and Ru 9 Pt 4 are all enhanced after interacting with [BMIM][CF 3 SO 3 ]. The stability enhanced degree is in agreement with the interaction strength. For Ru 7 Pt 6 –n{[BMIM][CF 3 SO 3 ]} (n = 1, 2, 3, 4), the interaction between ionic liquid and cluster plays the primary role in stabilizing the cluster in Ru 7 Pt 6 –[BMIM][CF 3 SO 3 ]. With the increase of the number of [BMIM][CF 3 SO 3 ], the role of the interaction in stabilizing the cluster is getting weaker, while the role of steric protection is getting more important.