Although you are able to use expired pecans when making a certain dish or eating them raw, it is not recommended as they will most likely be stale and unpleasant to eat. Those who want to avoid their pecans from becoming rancid and spoiling will want to put them in the freezer, especially if they are not going to be used for a while.
If you plan on using your nuts shortly after bringing them home from the supermarket, it is perfectly acceptable to just put them in the refrigerator until you need them. A lot of nuts have quite a bit of fat in them, including pecans, which means that it does not take long for them to become rancid, especially if they are left to sit out at room temperature for prolonged periods of time.