Performance of manganese-based catalyst comprising zinc oxide obtained from spent dry batteries for hydrocarbon oxidation

This study explores the potential of using spent dry batteries (SDBs) as catalysts to reduce environmental damage. The SDBs were separated into black mass (BM) and zinc rod (ZR), and the ZR material was treated with sulfuric acid to produce zinc oxide (ZO). Manganese (Mn)/ZO catalysts were synthesized with different Mn loadings and tested in the removal of o-xylene, toluene, and benzene. The results show that increasing Mn loading on ZO from 5.0 wt% to 30.0 wt% increased the catalytic decomposition of pollutants. The Mn species were well-dispersed on the ZO surface and existed in the oxidation states of Mn2+, Mn3+ and Mn4+, as confirmed by STEM/EDS and XPS, respectively. As Mn loading amount increased, the number of strong acid sites and the ratio of lattice oxygen to adsorbed oxygen (O 1sla/O 1sad) on the surface of the Mn/ZO catalyst increased, and the reduction temperature by H2 decreased. These surface properties had a significant impact on the catalytic activity. This study proposes a promising method that can contribute to both waste management and air quality improvement by recovering catalytic materials from SDBs and using them as catalysts for hydrocarbon removal.