I was just wondering when in history the official papal death sentences really ended. I am not interested in any killing that was not officially authorized by a pope (or his authorized representatives) as that would seem more like an potential unsanctioned action (even if done in the name of Catholic faith).
When official papal death sentence end? Never. Because it never started in the first place. Technically such a thing did not exist. Anathema was never officially meant death penalty.
But from your example of Jan Hus, I am assuming your question to be of the executions for holding heretical beliefs. Then the last person to be burned alive at the stake for that was Giordano Bruno, executed February 17, 1600. The last person to die (hanged to death) was Cayetano Ripoll, July 26, 1826.src
BTW the first one was Priscillian (d.385).
That said, I would like to make two points,
- Technically Church itself did not kill anyone, they just handed down heretics to secular authorities. (The link about Jan Hus that you mentioned in the comment explicitly mentions that too) The secular authorities wanted to kill heretics to maintain law and order in a city, which in turn will help them to keep up their power. The main aim of those inquisition is to protect the heretics from them and give them a last chance.
- Its not just the Catholics, protestants too did the same thing when they came to power. Thirty Years' War, Irish Martyrs, the English Martyrs, Boston martyrs, Salem Witch Hunt etc., are just examples. It is not to justify or defend any side's action, but just to say that the politics and culture is way too much different from ours today. And we cannot comprehend fully of what happened and why it happened to the fullest extend.