How to catch the Fatal Error in PHP?

Question

I'm facing with the Fatal error: Maximum execution time of 30 seconds exceeded.

I'm trying to catch this error and show the error message to user but it seems that "try...catch..." in PHP can't handle this.

I have tried to use "register_shutdown_function" but not success, the script continue to run and display blank page.

$max_execution_time = ini_get("max_execution_time");
ini_set('display_errors', false);
ini_set("max_execution_time", $max_execution_time * 0.8);
register_shutdown_function([$this, 'shutdownHandler']);

...

function shutdownHandler()
{
    $error = error_get_last();
    if (($error['type'] === E_ERROR) || ($error['type'] === E_USER_ERROR)) {
        ...
    }
}

Would anyone help me in this case?