Recovery and value-added utilization of critical metals from spent catalysts for new energy industry

With the rapid increase of new energy industry, the shortage of critical metals for new energy industry, such as Ni, Co, V, and Pt, has received global attention. The hazardous spent catalysts from traditional energy industry contain a series of critical metals, which should be safe disposal and even value-added utilized. However, the recovery of critical metals from these valuable wastes has not been well accepted. In this review, the characteristics and recycling necessity of spent catalysts are described in the start section, and then the current progress on stepwise recycling techniques of three typical spent catalysts are summarized, which are petroleum refining hydrogenation catalysts, platinum group metals catalysts and selective catalytic reduction catalysts. The regeneration and value-added utilization examples of these catalysts have been discussed and prospected. An overview of the advantage and disadvantage features of these techniques is presented, associating with the environmental assessment. At the end of the paper, the evolutions of metal elements and species of the recycling process are emphasized for rational designs and considerations from the mechanism of molecular level. The further perspective on the more practical value-added utilization is highlighted. This review set up a closed-loop conversion bridge from traditional energy wastes to new energy materials.