2800MT/s over PowerEdge Server

Hy.
My name is Costin.
I try to configure a PowerEdge Server . The interface from website it is very usefull, but i have a question.
Can i use RAM memory at 2800 MT/s? it will work? The motheboard will downclock the DIM Speed?
or what configuration i need or what settings i have to do, to make system work with memory at 2800MT/s?
I read this,
DIMM Speed

There is only one speed option for DDR4
2400MT/s – DIMMS will run at 1.2 vol
but i realy need to make system work with 2800 MT/s (128GB) (because I already bought them).
Thank you, and i wait for an answer (hope to be positive answer

Good day!