An apparatus for purifying impure hydrogen fuel is described that includes a first chamber and a second chamber. The first chamber is configured to receive impure hydrogen fuel in the form of a first mixture of gases with hydrogen gas and carbon monoxide at the first concentration while the second chamber is configured to receive a second mixture of gases with hydrogen gas at the second concentration. The apparatus also includes a solid-state electrolyte that separates the first chamber and the second chamber and includes an adsorbing catalyst. The apparatus also includes a pair of electrodes installed each in the first chamber and the second chamber to create a potential difference is created across the solid-state electrolyte.