Issue on sync powershell execution in .NET [duplicate]

I'd like to execute powershell commands in .NET framework, handling output and errors, but the following code failed executing any "complex"command.

    Process process = new Process();
    process.StartInfo.FileName = "cmd.exe";
    process.StartInfo.RedirectStandardInput = true;
    process.StartInfo.RedirectStandardOutput = true;
    process.StartInfo.RedirectStandardError = true;
    process.StartInfo.CreateNoWindow = true;
    process.StartInfo.UseShellExecute = false;
    process.StartInfo.WorkingDirectory = IsRoot(location);
    process.StartInfo.Arguments = string.Concat("/C powershell.exe /C ", cmd);
    process.Start();
    process.WaitForExit();
    string output = process.StandardOutput.ReadToEnd();
    string error = process.StandardError.ReadToEnd();
    process.Close();

    return (output, error);