Hilchos Shechita 2:18

Pursuant to the previous halacha, if a person slaughters an animal for a burnt offering, a peace offering, a thanksgiving offering or for the Pesach offering, the slaughtering is invalid. Since the Pesach offering can be designated each year at any time one likes, it’s comparable to a sacrifice that can be sanctified with a vow or a pledge. If one slaughters an animal for a sin offering, for a definite guilt offering, for a doubtful guilt offering, for a firstborn offering, for an animal tithe or as the exchange for some other sacrifice, the slaughter is valid.

Hilchos Shechita 2:19

Let’s say that someone is liable for a sin offering and he slaughters an animal saying that it’s for his sin offering. In such a case, his slaughtering is invalid. If he had an animal for a sacrifice in his home and he slaughtered an animal saying that it’s an exchange for his sacrifice animal, his slaughtering is invalid because he exchanged the animal for the sacrifice.