A solar fuels generator includes an anolyte and a catholyte in contact with a separator. The separator is configured such that the pH of the anolyte and the pH of the catholyte are each held at a steady state pH level during operation of the solar fuels generator. The steady state pH level of the anolyte is different from the steady state pH level of the catholyte.

According to one embodiment, a photochemical reaction system comprises a CO.sub.2 production unit, a CO.sub.2 absorption unit, and a CO.sub.2 reduction unit. The CO.sub.2 reduction unit comprises a laminated body and an ion transfer pathway. The laminated body comprises an oxidation catalyst layer producing O.sub.2 and H.sup.+ by oxidizing H.sub.2O, a reduction catalyst layer producing carbon compounds by reducing CO.sub.2 absorbed by the CO.sub.2 absorption unit, and a semiconductor layer formed between the oxidation catalyst layer and the reduction catalyst layer and develops charge separation with light energy. The ion transfer pathways make ions move between the oxidation catalyst layer side and the reduction catalyst layer side.

An electrode with a conductive substrate and an electrocatalyst comprising zinc oxide and copper oxide supported on a carbon nanomaterial, a method of fabricating the electrode, an electrochemical cell that utilizes the electrode as a working electrode, and a process for producing propanol from CO.sub.2 with the electrochemical cell. Various combinations of embodiments of the electrode and the method of fabricating thereof, the electrochemical cell, and the process for producing propanol from CO.sub.2 is provided.

Electrocatalysts composed of single atoms dispersed over porous carbon support were prepared by a lithium-melt method. The new catalysts demonstrated high selectivity, high Faradic efficiency and low overpotential toward to the electrocatalytic reduction of carbon dioxide to fuels.

A system and a method for the recovery of carbon dioxide from a gas containing it. The system of the invention includes: pressurizing means for pressurizing the gas, an absorption tank for absorbing into water the carbon dioxide contained in a gas pressurized with the pressurizing means, a desorption tank for desorbing from water the carbon dioxide absorbed in water, means for circulating water from the absorption tank into the desorption tank and from the desorption tank back into the absorption tank, and recovering means for the recovery of carbon dioxide capable of being desorbed from the water. The system's absorption tank houses an agitator with a function of enabling water to circulate in the absorption tank by ejecting it into an air space of the absorption tank and by spreading in the absorption tank's air space over an area as extensive as possible.

A proton-conductive electrochemical device and method for manufacturing the device. The device comprising a positive electrode able to reduce an oxidizing species, a negative electrode able to oxidize a reducing species, and a proton-conductive electrolyte, in contact with the positive and negative electrode. The device further comprises a layer able to diffuse protons and electrons, and forms a protective barrier against contaminants for the electrolyte. The layer is in contact with both the electrolyte and the negative electrode, and comprises a material of the type ABBO.sub.3 or a material of the type ABO.sub.3, wherein A is an element chosen from group II of the periodic table, B is an element chosen from cerium and group IVB of the periodic table, B is an element chosen from lanthanides or group VIIIB of the periodic table, and the layer has a porosity of less than 10% by volume.

The present embodiments provide a reduction catalyst realizing high reaction efficiency and a reduction reactor employing the catalyst. The reduction catalyst of the embodiment comprises an electric conductor and an organic layer having organic modifying groups placed on the surface of the conductor. The organic modifying groups have an aromatic ring having two or more nitrogen atoms. The reduction catalyst is used in a reduction reactor, and the reactor is also provided.

Disclosed are cathodes comprising a conductive support substrate having an electrocatalyst coating containing nickel phosphide nanoparticles. The conductive support substrate is capable of incorporating a material to be reduced, such as CO.sub.2 or CO. A co-catalyst, either incorporated into the electrolyte solution, or adsorbed to, deposited on, or incorporated into the bulk cathode material, provides increased selectivity and activity of the nickel phosphide electrocatalyst. Also disclosed are electrochemical methods for selectively generating hydrocarbon and/or carbohydrate products from CO.sub.2 or CO using water as a source of hydrogen.

A platform technology that uses a novel membrane electrode assembly, including a cathode layer, an anode layer, a membrane layer arranged between the cathode layer and the anode layer, the membrane conductively connecting the cathode layer and the anode layer, in a CO.sub.x reduction reactor has been developed. The reactor can be used to synthesize a broad range of carbon-based compounds from carbon dioxide and other gases containing carbon.

An electrochemical reduction device includes an electrode unit, a power control unit, an organic material storage tank, a concentration measurement unit, a water storage tank, a gas-water separation unit, and a control unit. The electrode unit includes an electrolyte membrane, a reduction electrode, and an oxygen evolving electrode. The control unit controls the power control unit so as to satisfy a relation of V.sub.HERV.sub.allowV.sub.CAV.sub.TRR when the potential at a reversible hydrogen electrode, the standard redox potential of the aromatic compound, and the potential of the reduction electrode are expressed as V.sub.HER, V.sub.TRR, and V.sub.CA, respectively. V.sub.allow is adjusted according to the concentration of the aromatic compound measured by the concentration measurement unit.