First principles calculations on the structures, electronic and magnetic properties of the TM_n@W12O36 (TM=Mn, Fe, Co and Ni, n =1–4) clusters

Transition metal (Mn, Fe, Co and Ni)-doped tungsten oxides nanoparticles with magnetic properties may be applied in various catalysts such as water treatment as they are easy to be recycled. Structural, electronic and magnetic properties of TM n @W[Formula: see text]O[Formula: see text] (TM=Mn, Fe, Co and Ni, [Formula: see text]=1–4) clusters have been calculated at PBE level. The results reveal that the centers of the TM[Formula: see text] clusters are in accordance with that of the W[Formula: see text]O[Formula: see text] clusters while the TM 4 clusters deviate obviously from the center of the W[Formula: see text]O[Formula: see text] cages. All TM n @W[Formula: see text]O[Formula: see text] clusters exhibit slightly less structural stability and obviously more chemical reactivity than the W[Formula: see text]O[Formula: see text] clusters. Mülliken spin densities of a TM atom embedded are almost kept except for the Ni@W[Formula: see text]O[Formula: see text] clusters. The spin densities of TM n clusters in the TM 3 @W[Formula: see text]O[Formula: see text] and TM 4 @W[Formula: see text]O[Formula: see text] clusters are offset. The magnetic TM modification strategy is helpful to design recyclable tungsten oxide catalysts.