Abstract: A system is disclosed for providing hydrogen that includes a first PEM electrochemical cell or stack including a membrane electrode assembly that includes an inlet for a first gas that comprises hydrogen in fluid communication with the anode side of the first electrochemical cell or cell stack, and an outlet in fluid communication with the cathode side of the first electrochemical cell or stack. A second electrochemical cell or cell stack includes a water inlet in fluid communication with the anode side of the second electrochemical cell or cell stack, and an outlet in fluid communication with the cathode side of the second electrochemical cell or cell stack. A controller is configured to operate the first electrochemical cell or cell stack as a primary hydrogen source and to controllably operate the second electrochemical cell or cell stack as a secondary hydrogen source.

Abstract: A method of operating an electrochemical cell stack is provided. The method includes feeding a reactant gas to the cell stack. The flow of the reactant gas is halted to at least one cell in the cell stack. The voltage applied to the at least one cell is increased. The flow of reactant gas to the at least one cell is initiated in response to the voltage increasing above a threshold for a predetermined amount of time.

Abstract: A method of operating an electrochemical cell stack is provided. The method includes feeding a reactant gas to the cell stack. The flow of the reactant gas is halted to at least one cell in the cell stack. The voltage applied to the at least one cell is increased. The flow of reactant gas to the at least one cell is initiated in response to the voltage increasing above a threshold for a predetermined amount of time.