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" style="font-family: 'FontAwesome', Arial" 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?