Font Awesome Icons in DropDownList Items

I want a select box with the font awesome icon and the name of the icon. I build my ListItems for the DropDownList in Code behind dynamically and want to show the icon with the unicode. Here is my output:

The decleration of the DropDownList looks like this:

 <asp:DropDownList ID="ddl_Icons" CssClass="form-control select2 fontawesomeselect" runat="server"></asp:DropDownList>

The font-family should be correct but there is still no icon displayed. Any tips how I can display the icons?

I'm using select2 and have made two CSS classes containing the following code:

<style type="text/css">
    .fontawesomeselect {
        font-family: 'FontAwesome', 'Arial';
    }

    .select2-selection__rendered{
        font-family: 'FontAwesome', 'Arial';
    }
</style>

via Chebli Mohamed