run the GP tool "create enterprise gdb" from ArcObjects

hello i work with arcobjects and c#.net , i try to create entreprise geodatabase in Postgresql using the following code

using ESRI.ArcGIS.Geoprocessor;
using ESRI.ArcGIS.DataManagementTools;

public void create_ent_geodatabase()
{
        Geoprocessor gp = new Geoprocessor();
        CreateEnterpriseGeodatabase ceg = new CreateEnterpriseGeodatabase();

        ceg.database_platform = "PostgreSQL";
        ceg.instance_name = "localhost";
        ceg.database_name = "database";
        ceg.database_admin = "postgres";
        ceg.database_admin_password = "password";
        ceg.gdb_admin_name = "sde";
        ceg.gdb_admin_password = "password";
        ceg.authorization_file = @"D:\server10.2.ecp";


        gp.Execute(ceg, null);
       }

but the operation failed i get the following message : Error HRESULT E_FAIL has been returned from a call to a COM component." at "gp.Execute"

any help will be appreciated!