An electrolytic cell equipped with microelectrodes for the generation of un-separated products and the method for obtaining it. The cell and the microelectrodes are obtained using a technology for the production of microelectromechanical systems (MEMS). The anodic and cathodic microelectrodes have an electrocatalytic coating and are mutually intercalated at an interelectrodic gap lower than 300 micrometres.

A system includes an airflow passage and an air purification element. The airflow passage is configured to confine a flow of air and direct the flow of air toward a space. The air purification element is positioned in the airflow passage and configured to produce a peroxide to oxidize contaminants in air flowing through the airflow passage. The air purification element includes a peroxide-generating structure and a matrix containing a peroxide-activating catalyst configured to activate peroxide produced. The air purification element is configured to produce the peroxide from a water vapor and oxygen in the air within the airflow passage when energized by an energy source, and the matrix is configured to allow the contaminants to contact peroxide activated by the peroxide-activating catalyst.

A system includes an airflow passage and an air purification element. The airflow passage is configured to confine a flow of air and direct the flow of air toward a space. The air purification element is positioned in the airflow passage and configured to produce a peroxide to oxidize contaminants in air flowing through the airflow passage. The air purification element includes a peroxide-generating structure and a matrix containing a peroxide-activating catalyst configured to activate peroxide produced. The air purification element is configured to produce the peroxide from a water vapor and oxygen in the air within the airflow passage when energized by an energy source, and the matrix is configured to allow the contaminants to contact peroxide activated by the peroxide-activating catalyst.

The invention relates to a process for electrolysis comprising a cathode and an anode comprising a catalyst, both the cathode and anode at least partly immersed in an electrolyte, the process characterised in that the electrolyte at least partly inhibits further oxidation of a product formed at the anode. Typically the catalyst comprises one or more metal-(Group VIb) semiconductors, and one or more metal-(GroupVIb))-phosphorous species.

The invention relates to a process for electrolysis comprising a cathode and an anode comprising a catalyst, both the cathode and anode at least partly immersed in an electrolyte, the process characterised in that the electrolyte at least partly inhibits further oxidation of a product formed at the anode. Typically the catalyst comprises one or more metal-(Group VIb) semiconductors, and one or more metal-(GroupVIb))-phosphorous species.

The present invention relates to a bio-electrochemical system (BES) and a method of in-situ production and removal of H.sub.2O.sub.2 using such a bio-electrochemical system (BES). Further, the invention relates to a method for in-situ control of H .sub.2O.sub.2 content in an aqueous system of advanced oxidation processes (AOPs) involving in-situ generation of hydroxyl radical (OH) by using such a bio-electrochemical system (BES) and to a method for treatment of wastewater and water disinfection. The bio-electrochemical system (BES) according to the invention comprises:—an aqueous cathode compartment comprising a first cathode and a second cathode,—an aqueous anode compartment comprising an anode at least partly covered in biofilm, wherein the first cathode is connected to a first circuit and the second cathode is connected to a second circuit, wherein the first and the second circuit are connected to the system by an external switch.

The present invention relates to a bio-electrochemical system (BES) and a method of in-situ production and removal of H.sub.2O.sub.2 using such a bio-electrochemical system (BES). Further, the invention relates to a method for in-situ control of H .sub.2O.sub.2 content in an aqueous system of advanced oxidation processes (AOPs) involving in-situ generation of hydroxyl radical (OH) by using such a bio-electrochemical system (BES) and to a method for treatment of wastewater and water disinfection. The bio-electrochemical system (BES) according to the invention comprises:—an aqueous cathode compartment comprising a first cathode and a second cathode,—an aqueous anode compartment comprising an anode at least partly covered in biofilm, wherein the first cathode is connected to a first circuit and the second cathode is connected to a second circuit, wherein the first and the second circuit are connected to the system by an external switch.

A method produces hydrogen peroxide in an aqueous solution by electrochemical reduction of oxygen. An oxygen containing gas is supplied to an electrochemically active side of a cathode contained in a cathodic compartment. The cathode contains a porous gas diffusion electrode, one side of which contains a carbon based electrochemically active layer capable of catalyzing the reduction of oxygen to hydrogen peroxide. The cathodic compartment is in fluid communication with an anodic compartment. At least one at least partly water soluble, weak protonic electrolyte is supplied to a catholyte. The weak protonic electrolyte has a pKa which is at least one unit higher than the pH of the catholyte at the onset of the oxygen reduction reaction to hydrogen peroxide. The catholyte is not pH buffered and the pH of the catholyte is let to evolve in course of the reaction.

A method produces hydrogen peroxide in an aqueous solution by electrochemical reduction of oxygen. An oxygen containing gas is supplied to an electrochemically active side of a cathode contained in a cathodic compartment. The cathode contains a porous gas diffusion electrode, one side of which contains a carbon based electrochemically active layer capable of catalyzing the reduction of oxygen to hydrogen peroxide. The cathodic compartment is in fluid communication with an anodic compartment. At least one at least partly water soluble, weak protonic electrolyte is supplied to a catholyte. The weak protonic electrolyte has a pKa which is at least one unit higher than the pH of the catholyte at the onset of the oxygen reduction reaction to hydrogen peroxide. The catholyte is not pH buffered and the pH of the catholyte is let to evolve in course of the reaction.

A catalyst for producing hydrogen peroxide and a preparation method therefor are provided. The catalyst for producing hydrogen peroxide according to the embodiments of the present invention comprises a carbon-based support and a catalyst moiety that is bonded to the carbon-based support and comprises an M.sub.1-N bonding structure (M.sub.1 represents a transition metal atom). The method for preparing a catalyst for producing hydrogen peroxide according to the embodiments of the present invention comprises comprises preparing a carbon-based support, providing a transition metal atom (M.sub.1) to the carbon-based support, and doping nitrogen into the carbon-based support.