Abstract: Herein discussed is an electrochemical reactor comprising a first electrode, wherein the first electrode is liquid when the reactor is in operation; a second electrode having a metallic phase and a ceramic phase, wherein the metallic phase is electronically conductive and wherein the ceramic phase is ionically conductive; and a membrane, wherein the membrane is positioned between the first and second electrodes and is in contact with the first and second electrodes, wherein the membrane is mixed conducting. Also discussed herein is a method of producing hydrogen or carbon monoxide comprising: (a) providing an electrochemical reactor having an anode, a cathode, and a membrane between the anode and the cathode, wherein the anode is liquid when the reactor is in operation and wherein the membrane is mixed conducting; (b) introducing a feedstock to the anode; (c) introducing a stream to the cathode, wherein the stream comprises water or carbon dioxide.

Abstract: Herein discussed is a method of producing carbon monoxide comprising: (a) providing an electrochemical reactor having an anode, a cathode, and a membrane between the anode and the cathode; (b) introducing a first stream to the anode, wherein the first stream comprises a fuel; and (c) introducing a second stream to the cathode, wherein the second stream comprises carbon dioxide, and wherein carbon monoxide is generated from carbon dioxide electrochemically; wherein the reactor comprises no interconnect and no current collector; wherein the reactor generates no electricity and receives no electricity; and wherein the reactor is operated at a temperature no higher than 750° C. In an embodiment, the reactor is operated at a temperature no higher than 700° C. or no higher than 650° C.

Abstract: A reactor assembly includes a multiplicity of electrochemical reactors, wherein each of the electrochemical reactors comprises an anode, a cathode, and a membrane between and in contact with the anode and the cathode, wherein the anode or the cathode forms a fluid passage having an inlet and an outlet, wherein the surface area of the fluid passage in contact with the anode or cathode is at least 25 times of the combined cross-sectional area of the inlet and the outlet; wherein the minimum distance between the reactors is no greater than 2 cm; and wherein the reactors have no interconnects and no direct contact with one another.

Abstract: An electrochemical reactor includes an anode, a cathode, and a membrane between and in contact with the anode and the cathode, wherein the anode or the cathode forms a fluid passage having an inlet and an outlet, wherein the surface area of the fluid passage in contact with the anode or cathode is at least 25 times of the combined cross-sectional area of the inlet and the outlet. Further discussed herein is an electrochemical reactor comprising an anode, a cathode, and a membrane between and in contact with the anode and the cathode, wherein the anode or the cathode forms a fluid passage having an inlet and an outlet, wherein a tortuosity of the fluid passage is no less than 10, wherein tortuosity is the ratio of fluid flow path length to the straight distance between the inlet and the outlet.

Abstract: Herein discussed is an electrochemical reactor comprising a first electrode, wherein the first electrode is liquid when the reactor is in operation; a second electrode having a metallic phase and a ceramic phase, wherein the metallic phase is electronically conductive and wherein the ceramic phase is ionically conductive; and a membrane, wherein the membrane is positioned between the first and second electrodes and is in contact with the first and second electrodes, wherein the membrane is mixed conducting. Also discussed herein is a method of producing hydrogen or carbon monoxide comprising: (a) providing an electrochemical reactor having an anode, a cathode, and a membrane between the anode and the cathode, wherein the anode is liquid when the reactor is in operation and wherein the membrane is mixed conducting; (b) introducing a feedstock to the anode; (c) introducing a stream to the cathode, wherein the stream comprises water or carbon dioxide.

Abstract: Herein discussed is a tubular comprising: an open end; an opposite closed end; and a mixed conducting membrane in at least a portion of the circumferential surface of the tubular. In an embodiment, the tubular comprises a cathode in contact with one circumferential side of the mixed conducting membrane and an anode in contact with the opposite circumferential side of the mixed conducting membrane. Methods of making and using such a tubular are also discussed herein.