How to select a particular node reference in a view programmatically
Within the views API, you could use this field as an argument and then use PHP to supply the default argument.  This would then restrict the views to all catalog_items that have that specific category node referenced.

If you are doing this in code/a module/template/etc, you could do it also like this:

$nid=WHATEVERPHPCODEYOUWANT;
return views_embed_view(VIEWNAME,'default',$nid); // 'default' is the views display