Insight into a Sustainable Application of Spent Lithium-Ion Cobaltate Batteries: Preparation of a Cobalt-Based Oxide Catalyst and Its Catalytic Performance in Toluene Oxidation

A cobalt-based oxide catalyst is prepared using recovered metals, such as cobalt, copper, manganese, and nickel, from spent lithium-ion cobaltate batteries, and its catalytic performance in toluene oxidation is investigated. The characterization results imply that the catalyst owns larger specific surface area, abundant mesopores, better reductivity at low temperature, stronger intensity of weak acid sites, and high concentrations of Co3+ ions and lattice oxygen species in comparison with a pure cobalt oxide. Furthermore, the catalytic evaluation tests indicate that the introduction of lithium can inhibit the catalytic activity, while the introduction of copper or manganese into pure cobalt oxide can improve the catalytic performance of toluene conversion. The in-situ diffuse reflectance Infrared Fourier transformations (DRIFT) study and thermal desorption/gas chromatography–mass spectrometry results indicate that benzaldehyde is the main byproduct derived during toluene oxidation over the as-prepared catalysts from waste at lower temperature, and the possible reaction pathway is investigated.