Additively Manufactured Zirconia-Supported Indium Oxide Catalysts and Their Performance in Direct Methanol Synthesis

In2O3/ZrO2-based materials
are
emerging as candidates for the next generation of industrial catalysts
for direct methanol synthesis. In this research, such catalysts were
additively manufactured into two distinct geometries that exhibit
different pressure drops and activity profiles, both among themselves
and in comparison to extrudates. The monoliths produced were comprehensively
characterized using a range of techniques, including gas sorption,
X-ray diffraction, micro X-ray fluorescence, and Raman mapping, to
verify their phase and chemical composition. Computational fluid dynamics
was employed to simulate the gas flow through these structures, corroborating
that the variations in the accessible surface area are the reason
for changes in their performance. Furthermore, the postreaction characterization
provides some insight into the catalysts’ degradation mechanisms
under hydrogen-rich conditions, identifying the migration of indium
oxide to the catalyst surface and pore blocking as possible causes
of the loss of activity.