Can I play Blitzcrank Impassive to an open battlefield?

No — normally you cannot. An "open" battlefield is uncontrolled and unoccupied (Rule 169.10.c), and you can only play units to your Base or a Battlefield you Control. An open battlefield isn't controlled by anyone, so it's not a valid location to play Blitzcrank to directly.

You can play Blitzcrank to a Battlefield you already control (triggering his ability to hook an enemy over), as confirmed by FAQ #3255. Playing him to an open battlefield requires an external effect like Miss Fortune, Buccaneer that explicitly lets you play a unit to an open battlefield (FAQ #7117).