A hydrogen diffusion cell that is used to purify contaminated hydrogen gas. The hydrogen diffusion cell has a supply tube that supplies contaminated hydrogen gas into a confined area and a drain tube that removes contaminated hydrogen gas from the confined area. Hydrogen permeable coils are disposed between the supply tube and the drain tube. The hydrogen permeable coils surround a perforated output tube that draws in any hydrogen gas that diffuses through the hydrogen permeable coils. The presence and position of the output tube prevent any significant lateral movement of hydrogen gas within the diffusion cell.