Can i supply the AREF pin with an Analog pin from the same board? I guess its a dumb question but couldnt find anything about it online. I know its possible to supply the AREF pin with 3.3 V to increase the ADC resolution. 

For the project i am working on the analog voltage i will be reading will be between 0 and 2.2 and the increased resolution is a must. 

I know i can use another board that has a 12 bit resolution but i really would like to make do with Uno. So i wonder if i can set an analog pin to output 2.3 V and feed it to the Aref pin.

If thats not possible please let me know why, so i can increase my knowledge
With an input voltage between 0 and 2.2 V, you can use a 2:1 voltage divider to cut the voltage in half.  In your code, use analogReference(INTERNAL) to set the analog reference voltage to 1.1 V.  The 1.1 V internal reference voltage is created by a bandgap circuit so is reasonably accurate.

To make the voltage divider, put two equal resistors (eg 10KΩ each) in series; connect one end of the series to your input voltage, the other end to ground, and the mid-point to an analog input pin.