Abstract: A gas electrode includes a plurality of stacked layers (2, 3, 4), wherein the first layer (2) is in contact with a solid substrate (1) while the last layer (4) has a free outer surface to be contacted with a gas, each layer being made of at least one mixed oxide selected from the group including perovskites and Ruddlesden-Popper phases, the micro-structure of the first layer (2) being different from that of the last layer (4), the porosity of the different layers (2, 3, 4) increasing from the first layer (2) towards the last layer (4), and the different layers stacked on each other defining a network of a solid interconnected material between the free outer surface of the last layer (4) and the solid substrate with a total thickness higher than 1 ?m. A method for making such an electrode and its use in an electrochemical cell are disclosed.

Abstract: The invention relates to an oxide material of general formula (I) A2?x?yA?XA?yM1?z M?Z04+?, wherein A and A? are independently a metal cation of a group formed by lanthanides and/or alkalis and/or alkaline earths, A? is a cationic gap, i.e. a cation vacancy A and/or A?, M and M? are independently a metal of a group formed by transition metals such as 0<y<0.30, preferably 0<y=0.20; 0<?<0.25, preferably 0<?<0.10; 0=x=1; and 0=z=1. An air electrode containing said material and an electric power producing device in the form of a fuel cell provided with at least one electrochemical cell comprising said electrode are also disclosed.

Abstract: The invention relates to a method for water electrolysis consisting in using an electrode containing at least one type of oxide material of general formula A2?x?yA?xA?yM1?zM?zO4+?, wherein A is a lanthanide and/or alkaline and/or alkaline earth metal cation, A? is at least one lanthanide and/or alkaline and/or alkaline earth metal cation, A? is a cation gap, M is a transition metal element, M? is at least one type of transition metal element, wherein said metal is such that 0<y<0.30, preferably 0<y?0.20; ?0 1??<0 25, preferably 0??<0.

Abstract: A method for preparing an oxide (P), which includes the steps of (i) forming a solid phase compound (O) based on an oxide containing molecular entities (1) chosen from optionally substituted ammonium, diammonium, diazan-ium or diazandium, the entities being distributed within the solid matrix, and (ii) eliminating the entities (1) from the solid phase compound (O) by reacting the solid phase compound (O) with a gaseous stream containing a break-down reactant for the entities (1), and isolating the resulting solid material (P).