Originally Posted by Nitro Zeus
No, there won't be any reward for that because we have to follow the method of prayer shown by the Prophet :saws: and not invent our own ways. Allah :swt: hears and knows everything but there is a prescribed way in which you've to pray the five daily prayers.
The function of mind and heart is to make the intention for prayer.
The function of mouth and tongue is to recite, and the function of hands, head, knees, feet etc is to raise, bow and prostrate in prayers. We cannot interchange their functions on our own.
The normal Dua outside prayers can be within the heart, but that is also better to be recited by mouth.