I confirm, you can not revoke any capability from administrator role. This role is for the site superadmin. If you need a role with permissions little bit lower than default admin, create a new role as a copy of administrator role and then revoke from it the capabilities which you don’t wish to leave there.

P.S. A lot of plugins check if user has ‘administrator’ role, not capabilities. While it’s not much correct, we always should check capability, not role, but it’s the fact. That’s why event if you revoke some capabilities from administrator role, such plugin still will provide full access for user with this role.