Disclosed herein is a method for selectively reducing, using electrical energy, CO.sub.2 to carbon monoxide or formic acid, a catalyst for use in the method, and an electrochemical reduction system. The method for producing carbon monoxide or formic acid by electrochemically reducing carbon dioxide of the present invention includes (a) reacting carbon dioxide with a metal complex represented by formula (1), and (b) applying a voltage to a reaction product of the carbon dioxide and the metal complex represented by formula (1):

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An arrangement for the electrolysis of carbon dioxide, includes: an electrolytic cell having an anode and a cathode, wherein the anode and cathode are connected to a voltage supply, wherein the cathode is configured as a gas diffusion electrode to which a gas compartment is attached on a first side and a cathode compartment is attached on a second side; an electrolyte circuit connecting to the electrolytic cell; and a gas supply for supplying carbon dioxide-containing gas into the gas compartment, wherein one or more channels are arranged in the gas compartment, wherein the channels are at least partially in contact with the gas diffusion electrode and are configured for transporting electrolyte fluid passing through the gas diffusion electrode to a lateral region of the gas compartment.

Electrochemically reacting C-1 compounds including carbon dioxide, formic acid, formaldehyde, methanol, carbon monoxide in the presence of at least one lanthanide and/or at least one actinide. Reducing carbon dioxide or reacting C-1 compounds such as HCOOH (formic acid), HCHO (formaldehyde), CH.sub.3OH (methanol), or CO (carbon monoxide) with use of an electrochemical device, wherein the device comprises at least one cathode, and at least one anode, and at least one electrolyte between the cathode and the anode, wherein the electrolyte comprises at least one lanthanide and/or actinide compound. The electrode can be modified with a film such as an ionically conducting or ionically permeable film, optionally comprising a magnetic material. Polar organic solvent such as acetonitrile can be used. Electrocatalysis and/or reaction mediation is observed. Devices can be adapted to carry out the methods. The device can be part of a fuel cell, a battery, an electrolyzer, or an electrosynthetic device.

The invention is directed to a method of electrochemically producing valeric acid.

The method of the invention comprises contacting a solution of levulinic acid with an anode and a cathode in an electrochemical cell; and electrochemically reducing levulinic acid at the cathode to form valeric acid,
wherein the cathode comprises one or more materials selected from the group consisting of cadmium, zinc, and indium.

A method of electrochemical reduction of carbon dioxide includes the use of multi-faceted Cu.sub.2O crystals as a catalyst to convert CO.sub.2 to value-added products. An electrochemical cell for the electrochemical reduction of carbon dioxide includes a cathode including the multi-faceted Cu.sub.2O crystals. The multi-faceted Cu.sub.2O crystals have at least two different types of facets with different Miller indices. The multi-faceted Cu.sub.2O crystals include steps and kinks present at the transitions between the different types of facets. These steps and kinks improve the Faradaic Efficiency of the conversion of carbon dioxide. The multi-faceted Cu.sub.2O crystals may be nanosized. The multi-faceted Cu.sub.2O crystals may include 18-facet, 20-facet, and/or 50-facet Cu.sub.2O crystals.

Some embodiments of the invention include methods of using a compound (e.g., Formula (I)) for the reduction of carbon dioxide to formate by contacting the carbon dioxide with a composition comprising a compound. In certain embodiments, the source of the carbon dioxide is air or is flue gas. Additional embodiments of the invention are also discussed herein.

The present disclosure relates to electrolysis. For example, an electrolysis system for carbon dioxide utilization may include: an electrolysis cell having an anode and a cathode, where carbon dioxide reduces at the cathode to at least one hydrocarbon compound or to carbon monoxide; first and second electrolyte reservoirs; a first product gas line from the first electrolyte reservoir; a second product gas line from the second electrolyte reservoir; a first connecting line supplying electrolyte from the first electrolyte reservoir to the anode; a second connecting line taking electrolyte from the anode to the second electrolyte reservoir; a third connecting line supplying electrolyte from the second electrolyte reservoir to the cathode; a fourth connecting line taking electrolyte from the cathode off to the first electrolyte reservoir; and a pressure-equalizing connection directly connecting the first and second electrolyte reservoirs.

A method for the substantially complete conversion of hydrogenous matter to higher value product, the method comprising: (i) subjecting the hydrogenous matter to a substantially complete deconstruction process in which an aqueous phase containing a multiplicity of deconstructed compounds is produced; and (ii) contacting the aqueous phase with an anode of a microbial electrolysis cell, the anode containing a community of microbes thereon which oxidatively degrade one or more of the oxygenated organic compounds in the aqueous phase to produce protons and free electrons at the anode, wherein the protons and free electrons are transported to the cathode to produce hydrogen gas or a valuable reduced organic compound at the cathode upon application of a suitable cell potential across the anode and cathode. The invention is also directed to an apparatus for practicing the method described above.

The embodiments provide an electrode catalyst layer for an electrolysis cell, and also an electrolysis cell and a carbon dioxide electrolysis apparatus comprising that layer. The catalyst layer has a controlled porous structure, and can realize a high partial current density. The catalyst layer of the embodiment comprises carbonous catalyst carriers, a metallic catalyst loaded on the carriers, and an ion-conductive material. The catalyst layer contains pores of 5 to 200 m diameters, and the pores have a volume per weight of the catalyst layer in the range of 3.0 to 10 mL/g in total.

Methods for reducing and regulating the acidification of water are provided. The method for reducing the acidification of water includes contacting at least one melanin material with the water and catalyzing a reaction between the water, CO.sub.2 and/or bicarbonate that produces glucose and increases pH of the water. The acidification of water is regulated by removing the at least one melanin material from the water once a desired pH of the water has been attained. The methods for reducing and regulating the acidification of water are particularly suited for the treatment of seawater that has been acidified by naturally occurring or artificially initiated reactions that increase free hydrogen ions in water, for example absorption of atmospheric carbon dioxide.