Catalog Layout
The Catalog layout does not exist in Journal > Layouts > Catalog... it needs to be created in Opencart > Design > Layouts...
Create a new layout, give it a name like Catalog, and then give it a new route of like so: https://cln.sh/v6Y4xWSN
You will then have the layout available in Journal > Layouts > Catalog... where you can activate the Left Column and add your Filter module to it. Just like it's on the Category layout.