Hook to track commerce product category view
Well, since you're dealing with Drupal, there's no "product category page"s ... per say ... but there are taxonomy terms that are often used for catalogs and attributes. So, you could, in theory, use hook_entity_view() to tap into when a taxonomy term is being viewed.

https://api.drupal.org/api/drupal/modules%21system%21system.api.php/function/hook_entity_view/7

If you're building a module, I could see you building an interface that lets people assign urls and taxonomy terms that would potentially "make" the catalog pages trigger whatever it is you want to trigger.

Ultimately, though, there's no hard and fast rule on how to build a commerce store, so there's nothing for you to hook into.