Is it proven to say this du'a before niyyah of salah?

> Inni Wajjhatu Wajhiya Lillazi Fataras Samawati Wal Ardha Hanifaun Wa Maa Ana Minal Mushrikeen. Translation: "I have made myself attentive towards Him who has created the earth & sky & I surrendered to Him. I am not one of those who associate something with Him." **Question:** This is done in Hanafi school but I want to know if there's an authentic Hadith. According to this article ["What Is Namaz"](http://www.islamic-web.com/namaz-salat/what-is-prayer/) it is said **before** the Niyyah. I thought the order was Niyyah, Takbeer, opening du'a (there's a few).