You will not be able to add to your eBay listings a link to your catalog, since this goes against eBay regulations.
But you can send out your PDF catalog in your newsletters and use it in social media to promote your eBay lisitngs.
You might also be interested in our Webstore solution, with which you can create a beautiful storefront for your eBay items and link it with each of your listings. You can learn more about it here: https://www.youtube.com/watch?v=tVqXy9g7sBM.
Feel free to leave a comment here if you have any questions.