Not for certain
Palpatine knew it was one of Anakin's options, but he didn't know which course of action Anakin would take in the end.
From the movie transcript:
PALPATINE: Are you going to kill me?
ANAKIN: I would certainly like to.
PALPATINE: I know you would. I can feel your anger. It gives you focus, makes you stronger.
ANAKIN raises his lightsaber to PALPATINE's throat. There is a tense moment, then ANAKIN relaxes, and then turns off his lightsaber.
ANAKIN: I am going to turn you over to the Jedi Council.
PALPATINE: Of course you should. But you're not sure of their intentions, are you? What if I am right and they are plotting to take over the Republic?
ANAKIN: I will quickly discover the truth of all this.
PALPATINE: You have great wisdom, Anakin. Know the power of the dark side. The power to save Padme.
ANAKIN stares at him for a moment.
PALPATINE turns and moves to his office.
PALPATINE: (continuing) I am not going anywhere. You have time to decide my fate. Perhaps you'll reconsider and help me rule the galaxy for the good of all . . .
PALPATINE sits behind his desk.
Palpatine leaves it up to Anakin. His hope is mainly that Anakin decides not to tell Windu and the rest of the council about his true identity, but instead joins him so that they can rule the galaxy together. Order 66 was going to be called anyway, so the Jedi would have been killed regardless of Anakin's decision.
Even when disarmed and practically helpless (lightning aside), Palpatine still uses the promise of being able to save Padme as a way to sway Anakin to his side, which ultimately works and causes Anakin to stop Windu from delivering the final blow. However, he didn't know that Anakin would do this. For pretty much his whole life, Palpatine has just been manipulating people and playing the probabilities. He's cold and calculating, but even he can't do anything with complete certainty. It's what makes him such a good villain.