A novel 3D printed technology to construct a monolithic ultrathin nanosheets Co₃O₄/SiO₂ catalyst for benzene catalytic combustion

In this study, a novel three-dimensional (3D)-OMm-Co₃O₄/SiO₂-0.5AP (OMm = ordered macro–meso porous, AP = aluminum phosphate) monolithic catalyst was for the first time constructed successfully with the hierarchical Co-phyllosilicate ultrathin nanosheets growth on the surface of 3D printed ordered macropore–mesoporous SiO₂ support. On the one hand, we discovered that the construction of ordered macropore–mesoporous structures is beneficial to the diffusion and adsorption of reactants, intermediates, and products. On the other hand, the formation of hierarchical Co-phyllosilicate ultrathin nanosheets could provide more active Co^&+ species, abundant acid sites, and active oxygen. The above factors are in favor of improving the catalytic performance of benzene oxidation, and then a 3D-OMm-Co₃O₄/SiO₂-0.5AP catalyst exhibited the superior catalytic activity. To explore the effect of catalysts structure and morphology, various Co-based catalysts were also constructed. Simultaneously, the 3D-OMm-Co₃O₄/SiO₂-0.5AP catalyst has excellent catalytic performance, water resistance, and thermal stability in the catalytic combustion of benzene due to the strong interactions between Co^&+ species and SiO₂ in the phyllosilicate. Therefore, this study proposes a new catalyst synthesis method through 3D printing, and presents considerable prospects for the removal of VOCs from industrial applications.