Abstract:
Metal ion conducting ceramic materials are disclosed having characteristics of high ion conductivity for certain alkali and monovalent metal ions at low temperatures, high selectivity for the metal ions, good current efficiency and stability in water and corrosive media under static and electrochemical conditions. The metal ion conducting ceramic materials are fabricated to be deficient in the metal ion. One general formulation of the metal ion conducting ceramic materials is Me1+x+y−zMIIIyMIV2−ySixP3−xO12−z/2, wherein Me is Na+, Li+, K+, Rb+, Cs+, Ag+, or mixtures thereof, 2.0≦x≦2.4, 0.0≦y≦1.0, and 0.05≦z≦0.9, where MIII is Al3+, Ga3+, Cr3+, Sc3+, Fe3+, In3+, Yb3+, Y3+, or mixtures thereof and MIV is Ti4+, Zr4+, Hf4+, or mixtures thereof.
Abstract:
Disclosed are processes of making solutions of alkali alkoxides in their corresponding alcohols using an electrolytic process. In one embodiment, sodium methoxide in methanol is made from methanol and aqueous sodium hydroxide solution, where the aqueous sodium hydroxide solution is present in the anolyte compartment and a solution of sodium methoxide in methanol is present in the catholyte compartment, the two compartments are separated by a ceramic membrane that selectively transports sodium ions under the influence of an electric potential, and wherein the composition of the solution of sodium methoxide in methanol in the catholyte compartment of the electrolytic cell comprises between at least about 2% by weight sodium methoxide and at most about 20% by weight sodium methoxide.
Abstract:
Alkali alcoholates, also called alkali alkoxides, are produced from alkali metal salt solutions and alcohol using a three-compartment electrolytic cell. The electrolytic cell includes an anolyte compartment configured with an anode, a buffer compartment, and a catholyte compartment configured with a cathode. An alkali ion conducting solid electrolyte configured to selectively transport alkali ions is positioned between the anolyte compartment and the buffer compartment. An alkali ion permeable separator is positioned between the buffer compartment and the catholyte compartment. The catholyte solution may include an alkali alcoholate and alcohol. The anolyte solution may include at least one alkali salt. The buffer compartment solution may include a soluble alkali salt and an alkali alcoholate in alcohol.
Abstract:
An improved gas diffusion electrode composed of a perovskite-type oxide dispersed in a mixture of carbon black and a hydrophobic binder polymer. An improved catalyst for use in the electrochemical reduction of oxygen comprising a perovskite-type compound having alpha and beta sites, and having a greater molar ratio of cations at the beta site. A particularly good reduction catalyst is a neodymium calcium manganite. An improved method of dispersing the catalysts with carbon in a reaction layer of the electrode improves performance of the electrode and the oxygen reduction process. This is provided by adding carbon black to an aqueous solution of metal salts before it is heated to a gel and then to a char and then calcined. Optionally, a quantity of the desired oxide catalyst can be premixed with a portion the carbon before adding the carbon to an aqueous solution of the metal salts to be heated. The amount of premixed metal oxide is chosen in conjunction with the amount of metal salts to provide the desired molar ratio after heating and calcining of the aqueous solution.
Abstract:
Disclosed are electrolytic cells for making solutions of metal alcoholates in their corresponding alcohols using an electrolytic process. In one embodiment, sodium methylate in methanol is made from methanol and sodium hydroxide solution. The sodium hydroxide solution is placed in the anolyte compartment and the methanol is placed in the catholyte compartment, and the two compartments are separated by a ceramic membrane that selectively transports sodium under the influence of current. In preferred embodiments, the process is cost-effective and not environmentally harmful.
Abstract:
A process is provided for synthesizing synthesis gas from carbon dioxide obtained from atmospheric air or other available carbon dioxide source and water using a sodium-conducting electrochemical cell. Synthesis gas is also produced by the coelectrolysis of carbon dioxide and steam in a solid oxide fuel cell or solid oxide electrolytic cell. The synthesis gas produced may then be further processed and eventually converted into a liquid fuel suitable for transportation or other applications.
Abstract:
An improved gas diffusion electrode composed of a perovskite-type oxide dispersed in a mixture of carbon black and a hydrophobic binder polymer. An improved catalyst for use in the electrochemical reduction of oxygen comprising a perovskite-type compound having alpha and beta sites, and having a greater molar ratio of cations at the beta site. A particularly good reduction catalyst is a neodymium calcium manganite. An improved method of dispersing the catalysts with carbon in a reaction layer of the electrode improves performance of the electrode and the oxygen reduction process. This is provided by adding carbon black to an aqueous solution of metal salts before it is heated to a gel and then to a char and then calcined. Optionally, a quantity of the desired oxide catalyst can be premixed with a portion the carbon before adding the carbon to an aqueous solution of the metal salts to be heated. The amount of premixed metal oxide is chosen in conjunction with the amount of metal salts to provide the desired molar ratio after heating and calcining of the aqueous solution.
Abstract:
An improved gas diffusion electrode composed of a perovskite-type oxide dispersed in a mixture of carbon black and a hydrophobic binder polymer. An improved catalyst for use in the electrochemical reduction of oxygen comprising a perovskite-type compound having alpha and beta sites, and having a greater molar ratio of cations at the beta site. A particularly good reduction catalyst is a neodymium calcium manganite. An improved method of dispersing the catalysts with carbon in a reaction layer of the electrode improves performance of the electrode and the oxygen reduction process. This is provided by adding carbon black to an aqueous solution of metal salts before it is heated to a gel and then to a char and then calcined. Optionally, a quantity of the desired oxide catalyst can be premixed with a portion the carbon before adding the carbon to an aqueous solution of the metal salts to be heated. The amount of premixed metal oxide is chosen in conjunction with the amount of metal salts to provide the desired molar ratio after heating and calcining of the aqueous solution.
Abstract:
A method is provided to recycle and synthesize aqueous alkali chemicals from industrial and radioactively contaminated alkali salt based waste streams using a two-compartment electrolytic cell having an alkali cation-conductive ceramic membrane. The processes and apparatus provide the capability of recycling and synthesizing value added chemicals, including but not limited to, alkali hydroxides.
Abstract:
Alkali alcoholates, also called alkali alkoxides, are produced from alkali metal salt solutions and alcohol using a three-compartment electrolytic cell. The electrolytic cell includes an anolyte compartment configured with an anode, a buffer compartment, and a catholyte compartment configured with a cathode. First and second separators are positioned between the anolyte compartment and the catholyte compartment to define a buffer compartment. The first and second separators are permeable to alkali ions. They may be fabricated of the same or different materials including, but not limited to, an alkali ion conducting solid electrolyte configured to selectively transport alkali ions, a porous ceramic, or a porous polymer separator material. The catholyte solution may include an alkali alcoholate and alcohol. The anolyte solution may include at least one alkali salt. The buffer compartment solution may include a soluble alkali salt and an alkali alcoholate in alcohol.