Asahi Kasei Kogyo Kabushiki Kaisha

Asahi Kasei Kabushiki Kaisha

Asahi Kasei Chemicals Corporation

Yasuhide Noaki

Hiroyoshi Houda

Saburo Okamoto

Yousuke Uchino

Kentaro Sako

Shinji Hasegawa

Kenji Nakagawa

Hiroyuki Shiroki

Masanobu Wakizoe

Keiji Miyoshi

Hisashi Wakamatsu

Provided are a gasket and an electrolyzer capable of preventing an electrolyte or a gas from leaking from a diaphragm. An annular gasket includes first and second surfaces which respectively contact a frame near a positive electrode and a frame near a negative electrode and a slit portion which is opened inward and is provided in the entire periphery of the gasket so as to accommodate an edge of an ion-permeable diaphragm.

Gasket and electrolyser

A bipolar alkaline water electrolysis unit incorporated in an electrolytic cell for electrolyzing an electrolytic solution of alkaline water to obtain oxygen and hydrogen, the bipolar alkaline water electrolysis unit including an oxygen generating anode, a hydrogen generating cathode, a conductive partition wall that separates the anode and the cathode from each other, and an outer frame that surrounds the conductive partition wall, wherein a gas and electrolytic solution passage is provided at an upper portion of the conductive partition wall and/or the outer frame, and an electrolytic solution passage is provided at a lower part of the conductive partition wall and/or the outer frame.

Bipolar alkaline water electrolysis unit and electrolytic cell

A bipolar zero-gap electrolytic cell comprising an anode comprising an anode substrate constituted of a titanium expanded metal or titanium metal net of 25 to 70% opening ratio, which anode after coating the substrate with a catalyst has a surface of 5 to 50 &#x3bc;m unevenness difference maximum and has a thickness of 0.7 to 2.0 mm. In this electrolytic cell, the possibility of breakage of ion exchange membrane is low, and the anolyte and catholyte have a concentration distribution falling within given range. With this electrolytic cell, stable electrolysis can be performed for a prolonged period of time with less variation of cell internal pressure.

Bipolar zero-gap type electrolytic cell

An electrode for use in hydrogen generation comprising a conductive base and a coating layer formed thereon of a composition obtainable by thermally decomposing, in the presence of an organic acid, a mixture comprising at least one type of platinum compound.

Electrode for use in hydrogen generation

Electrode for generation of hydrogen

Disclosed is a unit cell for use in a bipolar, filter press type electrolytic cell comprising a plurality of unit cells arranged in series through a cation exchange membrane disposed between respective adjacent unit cells, each unit cell comprising anode-side and cathode-side pan-shaped bodies having anode-side and cathode-side gas-liquid separation chambers respectively extending over the entire lengths of the upper sides of anode and cathode compartments, wherein the anode-side and cathode-side gas-liquid separation chambers have perforated bottom walls separating the anode-side and cathode-side gas-liquid separation chambers from the anode and cathode compartments, respectively, wherein a bubble removing partition wall is disposed at least in the anode-side gas-liquid separation chamber of both gas-liquid separation chambers and extends upwardly of the perforated bottom wall of the gas-liquid separation chamber and along the entire length of the gas-liquid separation chamber to partition the gas-liquid separation chamber into first and second passages A and B respectively formed in a perforated area and a non-perforated area of the bottom wall, wherein passage B communicates with a gas and liquid outlet nozzle, and wherein the bubble removing partition wall has an apertured segment having apertures which are positioned at least 10 mm above the inside surface of the bottom wall of the gas-liquid separation chamber.

Unit cell for alkali chloride metal aqueous solution electrolytic tank

Ion exchange membrane used for a fuel cell

Disclosed is a bipolar, filter press type electrolytic cell comprising a plurality of unit cells which are arranged in series through a cation exchange membrane disposed between respective adjacent unit cells, each unit cell containing anode-side and cathode-side gas-liquid separation chambers respectively disposed in anode-side and cathode-side non-current-flowing spaces and extending over the entire upper-side lengths of anode and cathode compartments. This electrolytic cell can be utilized to stably perform, for a prolonged period of time, the electrolysis of an aqueous alkali metal chloride solution at low cost without causing not only a leakage of an electrolytic solution but also vibration of the cell and formation of a gas zone in the upper portion of the anode and cathode compartments even in the electrolysis conducted at a high current density and at a high alkali concentration.

Bipolar, filter press type electrolytic cell

A highly durable, stable electrode having a coating comprised of an oxide of at least one metal selected from nickel and cobalt, which coating additionally contains titanium and zirconium components in proportions of 0.1. to 3.5% in terms of atomic percentage of titanium and 0.1 to 3% in terms of atomic percentage of zirconium, respectively. The electrode can advantageously be used in electrolyses in which hydrogen is evolved on the electrode, such as electrolyses of an alkali metal chloride and water. The electrode advantageously exhibits a low hydrogen overvoltage, enabling electrolysis to be performed stably for a prolonged period of time.

Hydrogen-evolution electrode having high durability and stability

A hydrogen-evolution electrode comprising an electrically conductive substrate having thereon a coating comprising a chromium component, a titanium component and an oxide of at least one metal selected from the group consisting of nickel and cobalt, said chromium component and titanium component being present in proportions, in terms of atomic percentage, of 0.5 to 40% and 0.1 to 10%, respectively. The titanium component retards the dissolution rate of the chromium component. Accordingly, the electrode has a life several times as long as that of the conventional electrodes, and can exhibit an advantageously low hydrogen overvoltage for a prolonged period of time. Also, the electrode can be advantageously employed to produce an alkali product improved in purity. Such a hydrogen-evolution electrode can be produced by melt-spraying onto a substrate a mixture of a finely divided powder of at least one member selected from the first group consisting of nickel, nickel compounds, cobalt and cobalt compounds, a finely divided powder of at least one member selected from the second group consisting of chromium and chromium compounds and a finely divided powder of at least one member selected from the third group consisting of titanium and titanium compounds. In the production, when the above-mentioned mixture is subjected to granulation and the obtained granules are melt-sprayed, there can be obtained the desired electrode having excellent properties with respect to catalytic activity and durability in high spraying yield.

Hydrogen-evolution electrode and a method of producing the same

An improved hydrogen-evolution electrode having thereon a coating containing an oxide of at least one metal selected from nickel and cobalt and further containing a chromium component in a proportion, in terms of atomic percentage, of 0.5 to 20% has been found to exhibit extremely low hydrogen overvoltage and to have not only high catalytic activity but also high durability. Such a hydrogen-evolution electrode can be produced by melt-spraying onto a substrate a mixture of a powder of at least one member selected from the first group consisting of nickel, cobalt, oxides of nickel and cobalt, hydroxides of nickel and cobalt, organic acid salts of nickel and cobalt and inorganic acid salts of nickel and cobalt and a powder of at least one member selected from the second group consisting of chromium, an oxide of chromium, a hydroxide of chromium, an organic acid salt of chromium and an inorganic acid salt of chromium. In the production, when the above-mentioned mixture is subjected to granulation and the obtained granules are melt-sprayed, there can be obtained the desired electrode having excellent properties with respect to catalytic activity and durability in high spraying yield.

Growing community of inventors

Nobeoka, Japan

Yasuhide Noaki