摘要:
The invention provides a multistep process for preparing a low-sulfur reformate gas for use in a fuel cell system. The process comprises catalytic steam reforming of a reactant gas mixture comprising sulfur-containing hydrocarbons and steam in a first step to make a reformate, reducing the carbon monoxide content of the reformate in a second step, passing the reformate over a sulfur absorber either directly after the first step or after passage through the second step, and desorbing the sulfur components optionally absorbed on the catalysts in the reforming and reducing process steps by periodically raising the temperature so as to cause the sulfer components to pass to the absorber, wherein the temperature of the absorber during operation of the process is always kept within a temperature interval which is an optimum for the absorber.
摘要:
The present invention relates to the field of electrochemical cells and fuel cells, more specifically to polymer-electrolyte-membrane (PEM) fuel cells and describes a process for the manufacture of membrane-electrode-assemblies (MEAs) containing five layers. The five-layer MEA is assembled together by means of a lamination process involving an adhesive component. The anode gas diffusion layer, the catalyst-coated membrane and the cathode gas diffusion layer are combined together by a low temperature/low pressure lamination process. Handling of the MEAs and assembly of the products into PEMFC and DMFC stacks is simplified. Less damage and perforation of the catalyst-coated membrane occurs and thus the performance of the five-layer MEAs is significantly improved.
摘要:
The present invention relates to a method for the production of a membrane electrode assembly comprising a polymer electrolyte membrane with two opposing membrane surfaces and a cathode and an anode electrode each comprising a catalyst layer and a gas distribution layer. Each catalyst layer is interposed between a membrane surface and the corresponding gas distribution layer. The catalyst layer of the cathode and/or the catalyst layer of the anode comprise at least two sub-layers. According to the present invention at least one of the sub-layers of the cathode electrode and/or the anode electrode is applied directly to the surface of the membrane while the remaining sub-layers are applied to the corresponding gas distribution layers. Finally the assembly of the coated membrane and the coated gas distribution layers is produced.
摘要:
This invention relates to a composition comprising nano-structured metal oxide particles (particularly, zirconia) and at least one stabilizing agent, a method to produce the composition, and a method to produce the thermally stable nano-structured particles. The method to produce the nano-structured particles comprises first preparing a base solution and a nanoparticle precursor solution, then combining these solutions at a final pH 7 or greater to precipitate a colloidal hydrous oxide. The colloidal hydrous oxide is then treated with at least one silicate, phosphate, or aluminum phosphate stabilizing agent and dried. These nano-structured particle products have high thermal stability and are particularly advantageous in applications as catalysts or catalyst supports that operate at high temperatures.