Solution:
I would recommend using preg_replace to strip out all special-chars from the title by only allowing letters and numbers (no special chars), i updated your code and posted an example:
add_shortcode( ‘custom_rss’, ‘execute_custom_rss_shortcode’ );
function execute_custom_rss_shortcode() {
$filtered_title = preg_replace(‘/[^a-zA-Z0-9]/’, ”, get_the_title());
// Remove any special character from the title
return do_shortcode(‘[wp_rss_retriever url=”https://news.google.com/rss/search?q=’ . $filtered_title . ‘&hl=en-US&gl=US&ceid=US%3Aen” items=”10″]’);
}