-- An electrolysis cell unit capable of efficiently electrolyzing water and carbon dioxide is obtained. An electrolysis cell unit includes at least an electrolysis cell in which an electrode layer and a counter electrode layer are formed with an electrolyte layer interposed therebetween and a discharge path for discharging hydrogen generated in the electrode layer, in which the electrolysis cell being formed in a thin layer on a support and a reverse water-gas shift reaction unit that generates carbon monoxide using carbon dioxide and the hydrogen by a reverse water-gas shift reaction being provided in at least a portion of the discharge path.--

A method includes collecting exhaust gas comprising carbon dioxide (CO.sub.2) at a wellsite to provide a collected exhaust gas, separating CO.sub.2 from the collected exhaust gas to provide a separated CO.sub.2, and forming urea utilizing at least a portion of the separated CO.sub.2. A system for carrying out the method is also provided.

A method includes collecting exhaust gas comprising carbon dioxide (CO.sub.2) at a wellsite to provide a collected exhaust gas, separating CO.sub.2 from the collected exhaust gas to provide a separated CO.sub.2, and forming urea utilizing at least a portion of the separated CO.sub.2. A system for carrying out the method is also provided.

A copper nanocatalyst, a method for preparing the copper nanocatalyst, and an application of the copper nanocatalyst in the synthesis of acetate or ammonia are provided. The copper nanocatalyst includes a substrate and an active agent loaded on the substrate. The method includes: preparing a cleaning agent by using an ethanol and a deionized; immersing the active agent in the cleaning agent, ultrasonically cleaning for 5-10 min at a frequency of 4×10.sup.4 Hz-8×10.sup.4 Hz, and drying for later use; mixing the cleaned active agent and a conductive binder according to a mass ratio of 1:19-9:1 of the active agent to the conductive binder, adding the ethanol, and fully stirring and dispersing to obtain a slurry; coating the slurry on a surface of the carbon paper, and drying the carbon paper by blowing through nitrogen flow to obtain the catalyst.

A reverse water-gas shift catalyst that can be used at a high temperature is obtained, and a production method thereof is obtained. The reverse water-gas shift catalyst is obtained by at least supporting one or both of nickel and iron as a catalytically active component on a carrier containing a ceria-based metal oxide or a zirconia-based metal oxide as a main component, and a ratio of the carrier to the entire catalyst is 55% by weight or more.

A reverse water-gas shift catalyst that can be used at a high temperature is obtained, and a production method thereof is obtained. The reverse water-gas shift catalyst is obtained by at least supporting one or both of nickel and iron as a catalytically active component on a carrier containing a ceria-based metal oxide or a zirconia-based metal oxide as a main component, and a ratio of the carrier to the entire catalyst is 55% by weight or more.

The present invention provides a process for incorporating at least one nano-catalyst on the surface of and within a plurality of pores of an electrode. The process includes spraying or dripping a catechol based surfactant onto the surface of and within one or more pores of a solid oxide electrochemical cell having an anode electrode and a cathode electrode; spraying or dripping a nano-catalyst solution onto the surface of and within one or more pores of the solid oxide electrochemical cell that has been pretreated with the catechol based surfactant for forming a modified solid oxide electrochemical cell; and firing the modified solid oxide electrochemical cell above a calcination temperature of the nano-catalyst solution for forming a nano-catalyst on the surface and within at least one or more pores of the solid oxide electrochemical cell.

An electrode catalyst layer for electrochemical cells includes a first catalyst layer and a second catalyst layer. The first catalyst layer has a cell resistance measured at 80° C. and 40% RH lower than that of the second catalyst layer. The electrode catalyst layer for electrochemical cells is used with the first catalyst layer being disposed on an electrolyte membrane side relative to the second catalyst layer. It is preferable that a first catalytically active component contained in the first catalyst layer and a second catalytically active component contained in the second catalyst layer each independently contain at least one element selected from the group consisting of platinum, palladium, ruthenium, and iridium.

An electrode catalyst layer for electrochemical cells includes a first catalyst layer and a second catalyst layer. The first catalyst layer has a cell resistance measured at 80° C. and 40% RH lower than that of the second catalyst layer. The electrode catalyst layer for electrochemical cells is used with the first catalyst layer being disposed on an electrolyte membrane side relative to the second catalyst layer. It is preferable that a first catalytically active component contained in the first catalyst layer and a second catalytically active component contained in the second catalyst layer each independently contain at least one element selected from the group consisting of platinum, palladium, ruthenium, and iridium.

A process for the preparation of a membrane electrode assembly comprising providing, in the following layer order, (I) a green supporting electrode layer comprising a composite of a mixed metal oxide and Ni oxide; (IV) a green mixed metal oxide membrane layer; and (V) a green second electrode layer comprising a composite of a mixed metal oxide and Ni oxide; and sintering all three layers simultaneously.