An electrochemical water gas shift system for removing low level carbon monoxide from hydrogen stream. The system including an electrolyzer having a porous anode for absorbing carbon monoxide from a hydrogen stream as a feed stream for a polymer electrolyte membrane fuel cell for generating an electrical energy, a small portion of electricity generated by the fuel cell is applied to the electrolyzer to convert carbon monoxide adsorbed in the porous anode to carbon dioxide and hydrogen via an electrochemical gas shift reaction without oxygen or air input. In an embodiment, the system includes a first electrolyzer operating as a CO adsorber and a second electrolyzer connected in parallel with the first electrolyzer operating as a CO remover. Two electrolyzers can be operated alternatively as CO adsorber and CO remover.