(349ae) A Novel Method of 3D Printing High-Loaded Oxide/H-ZSM-5 Catalyst Monoliths for Propane to Propylene Conversion

Oxidative propane dehydrogenation with CO₂ (ODPC) is an attractive catalytic method for propylene production, as it manufactures a valuable product and mitigates anthropogenic emissions. However, OPDC catalysts must be formed into structured contactors for use in industrial processes. Monolithic geometries are beneficial for this purpose, as their open channels improve mass transfer, reduce coking, and can be manufactured by 3D printing to fit any reactor geometry.^1-2 Previous iterations of 3D-printed catalytic monoliths were limited to 10 wt.% oxide loading, as the oxides were produced by dissolving their nitrate salts and hydrophobic pastes were observed at higher concentrations. This limited the propane conversion by OPDC to ~20%. We theorized that this could be addressed by increasing the catalyst loading. To accomplish this, we directly incorporated commercial oxides into the printing pastes, resulting in 15 wt.% Ga, Zr, V, and Cr single-oxide monoliths (85 wt.% H-ZSM-5) as well as one mixed metal sample which contained 5 wt.% Cr, 10 wt.% Ga, 10 wt.% V, 10 wt.% Zr, and 65% H-ZSM-5.³ The reaction experiments revealed that the vanadium-containing samples exhibited the best performance, where 40% propane conversion and 97% propylene selectivity were observed with and without CO₂. This being stated, all five monoliths produced by this method exhibited improved catalytic activity to their nitrate-based counterparts, as the propane conversion was above 30% for all samples and the propylene selectivity exceeded 90%. Moreover, the monoliths produced by direct oxide printing did not produce any BTX and showed less than 2% coking after 6 h. This study represents a novel way of manufacturing structured catalysts and demonstrates materials which outperform the state-of-art for ODPC propane conversion.

References

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3. Lawson et al. Adv. Sustain. Syst. 2020, 5, 1.