The present invention provides a process for preparing a water splitting catalyst containing [Mn.sub.4CaO.sub.4] core structure and use thereof. The present invention provides clusters containing [Mn.sub.4CaO.sub.4] core structure by a chemical synthesis using inexpensive metal ions (Mn.sup.2+, Ca.sup.2+ ions), simple carboxyl ligands and a permanganate, performed single crystal X-ray diffraction on their space structure, and characterized their physical and chemical properties with electron spectrum, electrochemical and electron paramagnetic resonance technologies and the like. These compounds can catalyze water splitting in the presence of oxidant to release oxygen and can also catalyze water splitting on the surface of an electrode to release electrons onto the surface of the electrode to form a current.

The present invention provides a process for preparing a water splitting catalyst containing [Mn.sub.4CaO.sub.4] core structure and use thereof. The present invention provides clusters containing [Mn.sub.4CaO.sub.4] core structure by a chemical synthesis using inexpensive metal ions (Mn.sup.2+, Ca.sup.2+ ions), simple carboxyl ligands and a permanganate, performed single crystal X-ray diffraction on their space structure, and characterized their physical and chemical properties with electron spectrum, electrochemical and electron paramagnetic resonance technologies and the like. These compounds can catalyze water splitting in the presence of oxidant to release oxygen and can also catalyze water splitting on the surface of an electrode to release electrons onto the surface of the electrode to form a current.

The invention is a cathode arrangement comprising a cathode housing (20) defining a space (16) for cathode material and comprising a cathode housing wall being permeable to an electrolyte, and a collector member made of carbon, having a first end part extending into the space (16) for cathode material and a second end part extending outside the space (16) for cathode material, and cathode particles (10), having a cylindric shape with a diameter of 2-5 mm and being extruded from carbon, are arranged in the space (16) for cathode material. The invention is, furthermore, an energy cell comprising the cathode arrangement, an arrangement for processing hydrogen gas comprising the cathode arrangement and use the energy cell applying seawater or salt water as an electrolyte. Furthermore, the invention is a method for manufacturing the cathode arrangement.

A fuel cell system includes a fuel cell having an anode and a cathode configured to output cathode exhaust. The fuel cell is configured to generate waste heat. The fuel cell system further includes a reformer configured to partially reform a feed gas using the waste heat and output a hydrogen-containing stream. The fuel cell system further includes a reformer-electrolyzer-purifier (“REP”) having an REP anode configured to receive a first portion of the hydrogen-containing stream and an REP cathode.

A fuel cell system includes a fuel cell having an anode and a cathode configured to output cathode exhaust. The fuel cell is configured to generate waste heat. The fuel cell system further includes a reformer configured to partially reform a feed gas using the waste heat and output a hydrogen-containing stream. The fuel cell system further includes a reformer-electrolyzer-purifier (“REP”) having an REP anode configured to receive a first portion of the hydrogen-containing stream and an REP cathode.

A reaction device comprising: a first flow path to which a fuel gas is supplied; a second flow path to which a gas containing oxygen is supplied; a hydrogen permeable membrane that separates the first flow path and the second flow path and allows hydrogen contained in the fuel gas supplied to the first flow path to permeate toward the second flow path; and a catalyst that is provided in the second flow path and promotes oxidation reaction between the oxygen and hydrogen passing through the hydrogen permeable membrane, wherein the hydrogen permeable membrane comprises a barium zirconium oxide membrane.

Disclosed is a carbon dioxide utilization system capable of recharging and undergoing reactions. The system includes a cathode unit provided with a first aqueous solution accommodated in a first accommodation space, and a cathode at least a part of which is submerged in the first aqueous solution; an anode unit provided with an alkaline second aqueous solution accommodated in a second accommodation space, and a metal anode at least a part of which is submerged in the second aqueous solution; and a connection unit provided with a connection channel connecting the first and second accommodation spaces in open communication, and a porous ion transfer member, disposed in the connection channel, for blocking the movement of the first and second aqueous solutions but allowing the movement of ions.

A controller according to an embodiment controls a hydrogen system including at least a hydrogen production system in which received power is planned in advance and a hydrogen production amount changes in accordance with the received power. The controller includes: a processor that calculates, in a preparation time period before a demand adjustment time period in which a target value of the received power is set in advance, a control command value such that input power to be inputted as the received power to the hydrogen production system matches the target value at a start of the demand adjustment time period; and a command controller that outputs the control command value calculated by the processor to the hydrogen production system.

The method for operating a water electrolysis device for generating hydrogen and oxygen from water has a PEM electrolyser (1), to which water for generating the hydrogen and the oxygen is supplied together with water for cooling. The cooling water is conducted in the circuit and treated by means of an ion exchanger unit (17). Only part of the water conducted in the circuit is supplied to the ion exchanger unit (17) and another part is supplied to the PEM electrolyser (1) via a bypass (13) circumventing the ion exchanger unit (17).

The method for operating a water electrolysis device for generating hydrogen and oxygen from water has a PEM electrolyser (1), to which water for generating the hydrogen and the oxygen is supplied together with water for cooling. The cooling water is conducted in the circuit and treated by means of an ion exchanger unit (17). Only part of the water conducted in the circuit is supplied to the ion exchanger unit (17) and another part is supplied to the PEM electrolyser (1) via a bypass (13) circumventing the ion exchanger unit (17).