What is the link between hydrogen production and potassium oxide?
When you react potassium and potassium hydroxide, you will produce potassium oxide and hydrogen as a byproduct.

$$\ce{2K + 2KOH -&gt;[\Delta] 2K2O + H2}$$


  Potassium react with potassium hydroxide to produce potassium oxide
  and hydrogen. This reaction takes place at a temperature near 450°C.(Chemiday)


The Wikipedia page of potassium oxide states:


  Potassium hydroxide cannot be further dehydrated to the oxide but it
  can react with molten potassium to produce it, releasing hydrogen as a
  byproduct.