NOVELTY - The membrane features a number of passageways where reactants and products which are diffusing through the membrane may be intercepted and flushed out using a gas or liquid. The passageways may also be coated with a catalytic layer capable of electrocatalytic oxidation of the intercepted fuel. A catalyst may also be used within the membrane without the use of a passage.    USE - Fuel cells, particularly direct methanol fuel cells.    ADVANTAGE - The approaches reduce or totally eliminate fuel crossover in fuel cells using organic fuels such as methanol, ethanol, dimethoxymethane, and trimethoxymethane.    DETAILED DESCRIPTION - A membrane comprises:    (a) ionically conducting sheet with a catalyst layer disposed within it; and    (b) metal current collector incorporated within the sheet in electronic communication with the catalyst.    INDEPENDENT CLAIMS are included for:    (A) a membrane comprising;    (i) a sheet of electronically insulating ion exchange material with a passage extending through it;    (ii) an electrocatalyst disposed along the inner wall of the passage;    (iii) a metal current collector incorporated into a portion of the sheet in electronic communication with the electrocatalyst.    (B) a method of reducing the amount of reactant or product crossover in an electrolytic cell comprising an anode, cathode, with a solid polymer electrolyte between them. The method comprises:    (i) allowing the reactant or product to enter the passage;    (ii) passing a fluid through the passage to receive the reactant or product and remove it from the cell along with the fluid.    (C) a method of manufacturing the membrane, comprising;    (i) coating at least a portion of a removable element with a catalyst;    (ii) forming a polymeric material around the catalyst and element to form a membrane with catalyst adhered to it;    (iii) removing the element from the membrane to leave a passage through the membrane.    (D) an alternative method of manufacturing the membrane, comprising;    (i) applying a catalyst to a surface portion of a first membrane sheet;    (ii) positioning a removable element between the first membrane sheet and a second membrane sheet with the catalyst layer facing the removable element;    (iii) bonding the two membrane sheets together;    (iv) removing the removable element to form a passage through the membrane.    (E) a method of forming a metal layer on an inside surface of a passage formed in an ion exchange material, comprising;    (i) contacting the inside surface of the passage with a solution of metal ions;    (ii) allowing the ions to exchange into the inner surface of the passage;    (iii) chemically reducing the exchanged ions to form a metal layer.    (F) a method of manufacturing the membrane comprising;    (i) applying a catalyst layer to a surface portion of a first membrane sheet;    (ii) bonding a second membrane sheet to the first sandwiching the catalyst layer between them.    DESCRIPTION OF DRAWING(S) - The drawing shows a membrane.    Nafion(TM) polymer electrolyte membranes (12, 14)    Catalyst layer (23)