I haven’t personally used these outdoors but as long as they are protected, I think they will work fine. I do have the Aeotec Z-wave multi-sensor that are rated for indoor/outdoor use. However, keep in mind that using motion sensors outdoors can give you a lot of false signals because they don’t sense actual motion but changes in infrared radiation. So sunlight going across your porch can set them off.
To reduce false motion events, you might want to take a look at this: