Recycling or refining of catalyst coated membrane components including those used in fuel cells or electrolysers; recycling or refining of catalyst materials including those used in fuel cells or electrolysers; recycling or refining of platinum group metal materials including those used in fuel cells or electrolysers; recycling or refining of ionomer materials including those used in fuel cells or electrolysers; recycling or refining of components used in fuel cells or electrolysers.