Highly Dispersed Pt Catalysts on Hierarchically Mesoporous Organosilica@Silica Nanoparticles with a Core-Shell Structure for Polycyclic Aromatic Hydrogenation

Hydrogenation of naphthalene can effectively reduce the content of aromatics in oil and generate high-value products. A series of Pt-based aluminum-modified core-shell-structured hierarchically peri-odic mesoporous organosilica@mesoporous silica nanoparticles (Pt/Al-x-PMOs@MSNs) were successfully synthesized and tested for the hydrogenation properties, with preferable mass transfer of macro -molecular reactants in the pores and increasing the total acidity of the catalysts. Moreover, the physicochemical properties of the core-shell-structured Pt-based catalysts were systematically analyzed using various characterization techniques. At 300 degrees C, the naphthalene conversion on the Pt/Al-10-PMOs@MSNs catalyst reached up to 100%, the selectivity of trans-decalin reached 83.9%, and the rate constants (k1, k2) and TOF were 13.2 x 10-6 mol center dot g-1 center dot s-1, 1.7 x 10-7 mol center dot g-1 center dot s-1, and 218.8 h-1, respectively. In the presence of sulfur, the naphthalene hydrogenation over the Pt/Al-10-PMOs@MSN catalyst first decreased to around 40% and then recovered to the original level, which originated from the synergistic effect of the texture and chemical properties over the Pt/Al-10-PMOs@MSNs with an excellent performance.

Automated summary

Hydrogenation of naphthalene can effectively reduce aromatic content in oil, and Pt-based aluminum-modified core-shell-structured nanoparticles showed excellent performance in this process. The synthesized Pt/Al-x-PMOs@MSNs catalysts exhibited preferable mass transfer and increased total acidity, leading to high conversion and selectivity of trans-decalin. The presence of sulfur had a temporary negative effect on naphthalene hydrogenation, but the catalysts ultimately recovered their original performance due to their unique texture and chemical properties.