Reaction of Hydrogen and Dinitrogen Tetroxide?
A likely reaction between dinitrogen tetroxide and hydrogen would be as follows with nitrogen and water being the products

$\ce{N2O4 + 4H2 → N2 + 4H2O~(I)}$

$\ce{\Delta H_{rxn}=[0+(4 x -241$.$ 8)-9$.$2 - (4 x 0)] ~=~ -976$.$4~ kJ}$

For the record, dinitrogen tetroxide and hydrazine (usually in combination with methylated hydrazines) is currently used as a rocket fuel.  The equation describing this reaction is

$\ce{N2O4 + 2N2H4 → 3N2 + 4H2O~(II)}$

$\ce{\Delta H_{rxn}=[(3 x 0) +(4~ x ~-241$.$ 8) - 9$.$2 - (2 x 50$.$6)] ~=~ -1077$.$6~ kJ}$