A supply system for providing at least oxygen depleted air and water in a vehicle includes a catalytic converter, at least one hydrogen supply means, at least one air supply means, at least one outlet for oxygen depleted air, and a control unit coupled with the catalytic converter. The catalytic converter is couplable with the hydrogen supply means and is adapted for producing water under consumption of hydrogen from the at least one hydrogen supply means and oxygen. The catalytic converter is further couplable with the at least one air supply means for additionally producing oxygen depleted air. Further, the control unit is adapted for selectively operating the catalytic converter based on a demand of water and oxygen depleted air.