Yes of course. In your shared premium web hosting account you have the option to select the PHP version through your cPanel and also enable or disable the PHP modules you wish to load with your PHP. To enable Phalcon in your PHP simply follow these instructions.
1- Login in your cPanel
2- Go to the "Software" section in the panel and click in the "Select PHP Version" icon/link.
3- Then select the PHP version you wish to run in your account. (If you wish you can change it)
4- Depending the PHP selected version you will be listed with the available modules for that PHP version. Check the "phalcon" module checkbox.
5- Then click in the "Ok" button to save your settings.