Highly Active Co3O4-Based Catalysts for Total Oxidation of Light C1-C3 Alkanes Prepared by a Simple Soft Chemistry Method: Effect of the Heat-Treatment Temperature and Mixture of Alkanes

Rut Sanchis; Adrián García; Francisco Ivars-Barceló; Stuart H Taylor; Tomás García; Ana Dejoz; María Isabel Vázquez; Benjamín Solsona

doi:10.3390/ma14237120

Highly Active Co₃O₄-Based Catalysts for Total Oxidation of Light C1-C3 Alkanes Prepared by a Simple Soft Chemistry Method: Effect of the Heat-Treatment Temperature and Mixture of Alkanes

Materials (Basel). 2021 Nov 23;14(23):7120. doi: 10.3390/ma14237120.

Authors

Rut Sanchis¹, Adrián García¹, Francisco Ivars-Barceló², Stuart H Taylor³, Tomás García⁴, Ana Dejoz¹, María Isabel Vázquez¹, Benjamín Solsona¹

Affiliations

¹ Departamento de Ingeniería Química, Universitat de València, C/Dr. Moliner 50, Burjassot, 46100 Valencia, Spain.
² Departamento Química Inorgánica y Química Técnica, Faculty of Sciences, UNED, Av. Esparta s/n, Las Rozas, 28232 Madrid, Spain.
³ Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK.
⁴ Instituto de Carboquímica (ICB-CSIC), C/Miguel Luesma 4, 50018 Zaragoza, Spain.

Abstract

In the present work, a simple soft chemistry method was employed to prepare cobalt mixed oxide (Co₃O₄) materials, which have shown remarkably high activity in the heterogeneously catalyzed total oxidation of low reactive VOCs such as the light alkanes propane, ethane, and methane. The optimal heat-treatment temperature of the catalysts was shown to depend on the reactivity of the alkane studied. The catalytic activity of the Co₃O₄ catalysts was found to be as high as that of the most effective catalysts based on noble metals. The physicochemical properties, from either the bulk (using XRD, TPR, TPD-O₂, and TEM) or the surface (using XPS), of the catalysts were investigated to correlate the properties with the catalytic performance in the total oxidation of VOCs. The presence of S1 low-coordinated oxygen species at the near surface of the Co₃O₄-based catalysts appeared to be linked with the higher reducibility of the catalysts and, consequently, with the higher catalytic activity, not only per mass of catalyst but also per surface area (enhanced areal rate). The co-presence of propane and methane in the feed at low reaction temperatures did not negatively affect the propane reactivity. However, the co-presence of propane and methane in the feed at higher reaction temperatures negatively affected the methane reactivity.

Keywords: alkane oxidation; cobalt oxide; ethane; heterogeneous catalysis; methane; propane; surface oxygen vacancies; total oxidation; volatile organic compounds.