Question: 

Is it permissible to perform a nafl qurbani or any nafl charitable act and then gift its reward to a person who is alive?

Answer: 

Yes, the reward of all Nafl Ibaadaat (whether it is Nafl Qurbani or any other Nafl charitable act) can be passed over to the living and deceased.

AND ALLAH TA’ALA ALONE IN HIS INFINITE KNOWLEDGE KNOWS BEST