Co₃O₄ particles were supported on a series of activated carbons (G60, CNR, RX3, and RB3). Incipient wetness method was used to prepare these catalysts. The effect of the structural and surface properties of the carbonaceous supports during oxidation of benzyl alcohol was evaluated. The synthetized catalysts were characterized via IR, TEM, TGA/MS, XRD, TPR, AAS, XPS, and N₂ adsorption/desorption isotherm techniques. Co₃O₄/G60 and Co₃O₄/RX3 catalysts have high activity and selectivity on the oxidation reaction reaching conversions above 90% after 6 h, without the presence of promoters. Catalytic performances show that differences in chemistry of support surface play an important role in activity and suggest that the presence of different ratios of species of cobalt and oxygenated groups on surface in Co₃O₄/G60 and Co₃O₄/RX3 catalysts, offered a larger effect synergic between both active phase and support increasing their catalytic activity when compared to the other tested catalysts.

En este trabajo se construyó y optimizó un sistema de gasificación a escala banco de residuos biomásicos (aserrín de pino). El sistema consta de una unidad de alimentación (tolva y tornillo), un reactor autotérmico de lecho fluidizado y acondicionamiento de gases (ciclón y enfriamiento). En el reactor se evaluaron 2 catalizadores de bajo costo: un mineral natural (dolomita) y residuo de pirólisis comparados con un sólido inerte (arena). Los catalizadores y la biomasa fueron caracterizados por diferentes técnicas: ICP, BET, TGA, CHONS, entre otras. En la optimización del proceso se estudiaron diferentes parámetros: tamaño de partícula de biomasa, flujo másico de alimentación, agentes gasificante y perfiles de temperatura. Los ensayos mostraron un óptimo funcionamiento con un tamaño de biomasa en el rango de 0.50-0.85 mm, un flujo másico de alimentación de 0.840 kg/h y una relación de equivalencia entre mezcla de agentes gasificantes (aire y/o vapor de agua) y alimentación de 0.35-0.45 con temperaturas de equilibrio de 650 y 750ºC, respectivamente. Los catalizadores evaluados tuvieron una reducción de alquitrán entre 10-45% comparado con el inerte y valores superiores en la relación H2:CO y LHV. Los resultados mostraron que el sistema de gasificación autotérmico a escala banco construido, permite la transformación de la biomasa utilizando catalizadores de bajo/nulo costo, lo que lo hace atractivo desde el punto de vista ambiental y económico.

Spent lithium-ion battery (LIB) cathodes were investigated as a multimetallic resource for catalyst precursor synthesis. Cathode material was leached under ultrasound using citric or sulfuric acid, with and without H₂O₂, to compare metal recovery, stability, and thermal transformation. Sulfuric acid with H₂O₂ achieved the highest extraction efficiencies, with 93.10% Co and 97.15% Mn, while Li extraction exceeded 95%. Maximum sulfuric concentrations were 12,822 mg L⁻¹ Co, 4588 mg L⁻¹ Mn, 185 mg L⁻¹ Ni, and 659 mg L⁻¹ Li. Initial citrate solution without H₂O₂ contained 25,870.90 mg L⁻¹ Co, 15,121.95 mg L⁻¹ Mn, 4118.14 mg L⁻¹ Li, 965.79 mg L⁻¹ Al, 162.74 mg L⁻¹ Cu, and 12.69 mg L⁻¹ Ni. Both liquors precipitated. The citrate system exhibited metal–citrate coordination, whereas the sulfuric system retained hydrated sulfate and aquo/sulfate species. After drying, the citrate precursor formed a carbon- and oxygen-rich matrix, while the sulfate precursor retained sulfur and oxygen at 400 °C. Citrate decomposition occurred at 200–400 °C, while sulfate transformation extended to approximately 612 °C. Reduction occurred at 400–900 °C for citrate and predominantly at 800–900 °C for sulfate. Both routes provide complementary precursor platforms for catalyst preparation; however, catalytic performance was not evaluated in this study and remains to be demonstrated.