Sponge-like carbon monoliths: Porosity control of 3D-printed carbon supports and its influence on the catalytic performance.

[Display omitted] • Carbon monoliths with tailored channel architecture and porosity were synthesized. • The PSD and macropore volume were controlled by varying the synthesis conditions. • Active-phase dispersion and gas diffusion through the carbon network were optimized. • The role that the monolith porosity plays in the catalytic performance was studied. • The potential of 3D printing to improve the catalytic supports is demonstrated. Sponge-like carbon monoliths with tailored channel architecture and porosity were prepared by combining sol–gel polymerization and 3D printing technology. The pore size distribution (PSD) and macropore volume were controlled by varying the water concentration used in the synthesis. The size and interconnection degree of primary particles, and consequently the pore width and macropores volume, increases by increasing the water concentration. However, a more heterogeneous PSD was detected at high water concentration, due to the better-defined spheres-like morphology of primary particles which leaves voids and corners between fused spheres together with bigger macropores leaves by the coral-like structure. The role of this porosity control on the CuO/CeO 2 catalytic performance was pointed out in the CO-PrOx reaction. The CuO/CeO 2 dispersion and distribution along the carbon network increases by increasing the water concentration, i.e. the pore width and macropore volume, enhancing the catalytic activity. However, this improvement is not observed at high water concentration in which preferential flow pathways are created favored by the heterogeneous PSD. This manifest that the porosity control plays an important role in the catalytic performance of monolithic catalysts and thus, the monolithic support must be specifically designed to optimize the catalytic performance of active phases for each application. [ABSTRACT FROM AUTHOR]