Techniques for photocatalytic hydrogen generation are provided. In one aspect, a hydrogen producing cell is provided. The hydrogen producing cell includes an anode electrode; a photocatalytic material adjacent to the anode electrode; a solid electrolyte adjacent to a side of the photocatalytic material opposite the anode electrode; and a cathode electrode adjacent to a side of the solid electrolyte opposite the photocatalytic material. A solar hydrogen producing system including at least one solar concentrating assembly having the hydrogen producing cell, and a method for producing hydrogen using the hydrogen producing cell are also provided.

A gas diffusion electrode for a membrane electrode assembly is provided with expanded metal layers each having a mesh configuration defining a length orientation of the expanded metal layers. The expanded metal layers each have opposed flat sides and are stacked in a layered arrangement such that the flat sides of the expanded metal layers that are neighboring each other in the layered arrangement are facing each other as facing flat sides, respectively. The facing flat sides are connected to each other by pulsed resistance welding at welded contact points. Due to the mesh configuration, the welded contact points are distributed evenly across the entire surface area of the facing flat sides. At least one of the expanded metal layers is oriented with its length orientation so as to be rotated by 90° relative to the length orientation of one of the neighboring expanded metal layers.

A heat exchanger can be integrated into an interconnector that can be used in both a SOFC fuel cell and an EHT electrolyser, which allows a heat-transfer fluid different from that in the reactive and drainage gas circuits to be circulated from the inlet of the reactor, thereby allowing the best possible management of the exothermic operating modes of the SOFC cell and the exothermic or endothermic operating modes of the EHT electrolyser and the SOFC cell, especially in the absence of current for the latter.

An electrochemical reaction device includes: an electrolytic solution tank including a first storage part to store a first electrolytic solution, and a second storage part to store a second electrolytic solution; a reduction electrode disposed in the first storage part and having a first surface; an oxidation electrode disposed in the second storage part and having a second surface; and a generator connected to the reduction and oxidation electrodes. A region in the first storage part between the first surface and an inner wall of the first storage part is an electrolytic solution flow path. The electrolytic solution flow path has a maximum part and a minimum part.

A catalyst comprising particles of iridium oxide and a metal oxide (M oxide), wherein the metal oxide is selected from the group consisting of a Group 4 metal oxide, a Group 5 metal oxide, a Group 7 metal oxide and antimony oxide, wherein the catalyst is prepared by subjecting a precursor mixture to flame spray pyrolysis, wherein the precursor mixture comprises a solvent, an iridium oxide precursor and a metal oxide precursor is disclosed. The catalyst has particular use in catalysing the oxygen evolution reaction.

A hydrogen water manufacturing system includes: a container-shaped constant pressure maintaining unit receiving water and maintaining a water level; an electrolysis unit including a hermetically sealed container bisected into an oxygen generation chamber and a hydrogen generation chamber with an ion exchange membrane interposed therebetween, wherein the chambers independently receive the raw water from the constant pressure maintaining unit, and a positive electrode plate is provided in the oxygen generation chamber and a negative electrode plate is provided in the hydrogen generation chamber; a fluid pump receiving the water and hydrogen from the hydrogen generation chamber; a dissolution unit having a nozzle to inject the water and the hydrogen supplied from the fluid pump; and a flow rate detection sensor arranged on piping downstream of the dissolution unit to detect supply of hydrogen water and drive the fluid pump and simultaneously supply electrical power to the electrolysis unit.

An electrochemical reaction device includes: a first electrolytic solution tank including first and second storage parts storing first and second electrolytic solutions containing carbon dioxide and water respectively; reduction and oxidation electrodes immersed in the first and second electrolytic solutions respectively; a generator connected to the reduction and oxidation electrodes; a second electrolytic solution tank including a third storage part storing a third electrolytic solution containing carbon dioxide; and a flow path connecting the first and third storage parts. The third electrolytic solution is lower in temperature than the first electrolytic solution.

Water electrolyzers employs base metal catalysts and an anion-conducting polymeric membrane comprising a polymer of styrene, vinylbenzyl-R.sub.s and possibly vinylbenzyl-R.sub.x. R.sub.s is a positively charged cyclic amine group. R.sub.x is at least one constituent selected from the group consisting of —Cl, —OH, and a reaction product between an —OH or —Cl and a species other than a simple amine or a cyclic amine.

The invention provides electro-catalyst compositions for an anode electrode of an acid mediated proton exchange membrane-based water electrolysis system. The compositions include a noble metal component selected from the group consisting of iridium oxide, ruthenium oxide, rhenium oxide and mixtures thereof, and a non-noble metal component selected from the group consisting of tantalum oxide, tin oxide, niobium oxide, titanium oxide, tungsten oxide, molybdenum oxide, yttrium oxide, scandium oxide, cooper oxide, zirconium oxide, nickel oxide and mixtures thereof. Further, the non-noble metal component can include a dopant. The dopant can be at least one element selected from Groups III, V, VI and VII of the Periodic Table. The compositions can be prepared using any solution based methods involving a surfactant approach or a sol gel approach. Further, the compositions are prepared using noble metal and non-noble metal precursors. Furthermore, a thin film containing the compositions can be deposited onto a substrate to form the anode electrode.

The present invention relates to a process for the preparation of Calcium Silicate Hydrate anion exchange membrane (cement paste) with an ionic conductivity of the order of 10.sup.−3 S/cm. The membrane can be formulated by mixing Ordinary Portland Cement (OPC) and water with the cement to water ratio of 1:0.45. After initial setting time, the membrane undergoes curing in 7% calcium chloride solution and the Cl.sup.− ions in the membrane is converted to OH.sup.− form by immersing into saturated Ca(OH).sub.2 solution with pH 14 and it has been washed to remove the excess alkali. This membrane has high mechanical strength (Ultimate Tensile Strength: 6.3 MPa) and does not deteriorate even at high temperature (up to 450° C.) and alkaline atmosphere (pH 11.5-14). Also disclosed is a method of producing in-situ formation of membrane electrode assembly. This invention encompasses a process for producing and using the membrane in water electrolysis and fuel cell.