# Are there chemicals that absorb and release upon heating oxygen more efficiently than potassium oxide? [closed]

$$\ce{K2O}$$ absorbs oxygen forming $$\ce{K2O2},$$ which decomposes to $$\ce{K2O}$$ and $$\ce{O2}$$ at 500 °C. This means that $$\ce{K2O}$$ can absorb up to 17% its mass of oxygen. Are there other substances that exceed this ratio and release oxygen below 1000 °C?