<styleSheet
  xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main"
  xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
  mc:Ignorable="x14ac x16r2"
  xmlns:x14ac="http://schemas.microsoft.com/office/spreadsheetml/2009/9/ac"
  xmlns:x16r2="http://schemas.microsoft.com/office/spreadsheetml/2015/02/main" />

var src = new ActiveXObject("MSXML2.DomDocument");
src.async = false;
if (!src.load("D:\\Trash\\1.xml"))
{
  WScript.Echo("Error loading XML: "+src.parseError.reason+"/"+src.parseError.errorCode);
  WScript.Quit(1);
}
var attributes = src.documentElement.selectNodes("@*");
for(var i=0; i<attributes.length-1; i++)
  WScript.Echo(attributes[i].name+" "+attributes[i].value);
WScript.Echo("done");

D:\Trash>cscript.exe 1.js
Сервер сценариев Windows (Microsoft ®) версия 5.812
Copyright (C) Корпорация Майкрософт 1996-2006, все права защищены.

xmlns  http://schemas.openxmlformats.org/spreadsheetml/2006/main 
xmlns:mc  http://schemas.openxmlformats.org/markup-compatibility/2006 
mc:Ignorable x14ac x16r2
xmlns:x14ac  http://schemas.microsoft.com/office/spreadsheetml/2009/9/ac 
done

declare
  @x nvarchar(max)=N'<styleSheet
  xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main"
  xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
  mc:Ignorable="x14ac x16r2"
  xmlns:x14ac="http://schemas.microsoft.com/office/spreadsheetml/2009/9/ac"
  xmlns:x16r2="http://schemas.microsoft.com/office/spreadsheetml/2015/02/main" />',
  @h int;
exec sp_xml_preparedocument @h out, @x;
select * from openxml(@h, '//@*', 1)
with (
  pfx sysname '@mp:prefix',
  name sysname '@mp:localName',
  value sysname '.'
);
exec sp_xml_removedocument @h;

pfx      name         value
-------- ------------ ----------------------------------------------------------------
xmlns                  http://schemas.openxmlformats.org/spreadsheetml/2006/main 
xmlns    mc            http://schemas.openxmlformats.org/markup-compatibility/2006 
mc       Ignorable    x14ac x16r2
xmlns    x14ac         http://schemas.microsoft.com/office/spreadsheetml/2009/9/ac 
xmlns    x16r2         http://schemas.microsoft.com/office/spreadsheetml/2015/02/main 

(5 rows affected)

var xd = new XmlDocument();
xd.Load(@"D:\Trash\1.xml");
foreach (var a in xd.DocumentElement.SelectNodes("//namespace::*").Cast<XmlAttribute>())
  Console.WriteLine("{0} {1}", a.Name, a.Value);

xmlns:x16r2  http://schemas.microsoft.com/office/spreadsheetml/2015/02/main 
xmlns:x14ac  http://schemas.microsoft.com/office/spreadsheetml/2009/9/ac 
xmlns:mc  http://schemas.openxmlformats.org/markup-compatibility/2006 
xmlns  http://schemas.openxmlformats.org/spreadsheetml/2006/main 
xmlns:xml  http://www.w3.org/XML/1998/namespace