From trash to resource: recovered-Pd from spent three-way catalysts as a precursor of an effective photo-catalyst for H2 production

Abstract

The successful production of a nanostructured and highly dispersed Pd-TiO₂ photo-catalyst, using [Pd(Me₂dazdt)₂](I₃)₂ (Me₂dazdt = N,N′-dimethyl-perhydrodiazepine-2,3-dithione) salt, obtained through the selective and safe recovery of palladium from model exhaust three-way catalysts (TWCs), is reported here. The photo-catalyst prepared by the impregnation/photo-reduction of palladium on the support showed improved performance in H₂ production from methanol and in glycerol photo-reforming compared to reference photo-catalysts obtained from conventional Pd-salts. The reported results represent a case of successful palladium “recovery and re-employment” and thus constitute an example of green chemistry by providing, in one route, the environmentally friendly recovery of a critical metal and its employment in the renewable energy field.