I have never heard of something like a "gate pass" in Zurich - not saying it does not exist though, but in my years working there, I have not come across them.
Unless the person is handicapped, very young or very old, I don't think the airline handling agent will have somebody available to take of him, either.
Perhaps you should look into the airport's
VIP Service and ask if they have Portuguese-speaking staff?
Otherwise, the refundable ticket may work but you'll need a boarding pass (i.e. be checked in) to get airside. Make sure you can still cancel after checking.