Can a porcelain veneer be placed over a new zirconium crown?

Why ? Why would your dentist place a veneer over a new crown? It there is something wrong with the new crown, the better option is just to remake it.
A weak patch! The bond of the veneer to the crown would be weak at best and not hold up well. In addition, the restoration would tend to be bulky. In my opinion the attempt would be nonsensical. Better to remake the crown with the needed corrections.
Why? If its new .... & you are doing it for color or shape.... change the things yo don't like in the actual crown.
Why? If you are unhappy with a new crown the best thing for you to do is to see your dentist and discuss your concerns with them. It will generally not work to place a veneer on a crown.
Yes it is possible. It can be done by using hydrofluoric acid, bonding agent and resin cement. Take care.