Recovery technology of spent hydrogenation catalysts -A review.

Spent hydrogenation catalysts (HDCs) contain many Mo, V, Co, Ni, and AlO carriers, which are valuable secondary resources. However, improper disposal can also lead to environmental pollution risks. In the past decade, research reviews on the recovery of valuable metals from spent HDCs have been somewhat reported, mainly summarizing basic technical processes.

Highly dispersed Ir/Fe nanoparticles anchored at nitrogen-doped activated pyrolytic carbon black as a high-performance OER catalyst for lead recovery.

The use of a methanesulfonic acid (MSA) electrolytic system is recommended as a green method for hydrometallurgical recovery of metallic Pb from waste lead-acid batteries (LABs), contributing to the sustainable protection of the ecosystem. Nevertheless, the system's high energy consumption is a current issue due to the substantial overpotential of the oxygen evolution reaction (OER) and competitive anodic oxidation of Pb. Herein, we propose an IrFe/nitrogen-doped pyrolytic carbon black (IrFe/NCBp) composite as a novel OER catalyst for the MSA electrolytic system, which demonstrates advanced OER catalytic efficiency and selectivity for HO oxidation.