Where can I donate print academic journals?
Most US institutions have subscriptions to the most important journals that include online access of past content -- so they will generally not have any interest in stocking yet more paper in their archives.

This is different for developing countries where space is less expensive than journal subscriptions. I've had colleagues will connections to third world universities to which they always took boxed of books donated by colleagues every time they went. I suspect that if you ask around enough, you'll find colleagues who know someone in Africa or Southeast Asia who would be interested in taking books and journals -- but you may have to pay for shipping.