The word "particular" as an adjective is used to indicate or point out an individual object, item, quality etc. "Special" is an adjective synonymous with "particular" but is used to describe something that has certain distinctive or uncommon properties. Hope this helps!

They are synonymous. However, 'special' is usually creates a better image, an image of something good, even though 'particular' could also be used. If somebody has a special quality, it is generally taken to mean that the quality is good. If that same person as a particular quality, it is not necessarily taken to be positive. Again, this is cultural, rather than by a strict definition.