Precious metal catalyst recycling through photocatalytic dissolution†

Abstract

Precious metal (PM) catalysts have been widely used in the chemical industry owing to their high activity, selectivity and stability. The key problems are their scarcity and high cost. Therefore, the recycling of PMs from deactivated catalysts becomes a critical step in industry. Here, we developed a novel recycling method for the photoresponsive carrier-supported Au-based PM catalyst through an eco-friendly photocatalytic dissolution technique. Au is recovered effectively from deactivated Au/CeO₂ using itself as the photocatalyst and re-deposited on the remaining CeO₂. The revived Au/CeO₂ exhibits comparable performance with the fresh catalyst during ethane dehydrogenation either in the absence or in the presence of CO₂. Similar results can also be obtained over the Pt/CeO₂ catalyst recovered from a deactivated catalyst using this all-in-one dissolution–deposition technique. In comparison with the conventional methods, this recycling preparation offers a more environmentally friendly and long-lasting method for efficiently recycling PMs and producing regenerated PM catalysts.