Catalyst material for producing oxygen gas from water
AssigneeKyoto University
InventorHideki Koyanaka
Life of this patent
Estimating the term…
Abstract
Provided is a catalyst material comprising aggregates of nanoneedles of mainly R-type manganese dioxide and having a mesoporous structure. With this, water can be oxidatively decomposed under visible light at room temperature to produce oxygen gas, proton and electron. Also provided is a catalyst material comprising aggregates of nanoparticles of mainly hydrogenated manganese dioxide. With this, acetic acid or an inorganic substance can be synthesized from carbon dioxide gas.
Claims27
A catalyst material for producing oxygen gas, proton and electron by oxidatively decomposing water, which comprises aggregates of nanoneedles of mainly R-type manganese dioxide and has a mesoporous structure.
A catalyst material for producing acetic acid or an organic substance from carbon dioxide gas, which comprises aggregates of nanoparticles of mainly hydrogenated manganese dioxide having an R-type crystal structure and an epsilon-type crystal structure.
A method for producing a catalyst material for producing oxygen gas, proton and electron by oxidatively decomposing water, which comprises burning a divalent manganese compound, followed by acid-treating and thereafter drying the compound,
- wherein the divalent manganese compound is manganese carbonate.
A method for producing a catalyst material for producing acetic acid or an organic substance from carbon dioxide gas, which comprises burning a divalent manganese compound, and then acid-treating the compound,
- wherein the divalent manganese compound is manganese carbonate.
A method for synthesizing acetic acid, comprising the steps of:
- Burning a manganese carbonate and acid-treating it with an acid-treating liquid to obtain carbon dioxide gas and a paste of aggregates of nanoparticles of mainly hydrogenated manganese dioxide having an R-type crystal structure and an epsilon-type crystal structure, and
- contacting the paste of aggregates of nanoparticles with the carbon dioxide gas to obtain acetic acid.
A method for synthesizing a saccharide, comprising the steps of:
- burning a manganese carbonate and acid-treating it with an acid-treating liquid to obtain a paste of aggregates of nanoparticles of mainly hydrogenated manganese dioxide having an R-type crystal structure and an epsilon-type crystal structure, and
- drying the paste of aggregates of nanoparticles in air, wherein a liquid containing saccharide is bled out from the paste of aggregates of nanoparticles.
A method for recycling an acid-treatment liquid (waste liquid), which comprises burning a divalent manganese compound, followed by acid-treating the compound to obtain the acid-treatment liquid, adding an oxidizing agent and an alkali compound to the acid-treatment liquid to thereby precipitate manganese oxide, then acid-treating, and drying the manganese oxide precipitate to obtain R-type manganese dioxide.
A method for recycling an acid-treatment liquid (waste liquid), which comprises burning a divalent manganese compound, followed by acid-treating the compound to obtain the acid-treatment liquid, and adding potassium permanganate to the acid-treatment liquid to obtain manganese dioxide.
A method for recycling an acid-treatment liquid (waste liquid), which comprises burning a divalent manganese compound, followed by acid-treating the compound to obtain the acid-treatment liquid, and adding an alkali metal or alkaline earth metal carbonate to the acid-treatment liquid to obtain manganese carbonate.
Dependencies are inferred from the claim text.