Ring opening of decalin and methylcyclohexane over bifunctional Ir/WO3/Al2O3 catalysts

Ring opening of decalin over bifunctional Ni–W carbide/Al2O3–USY catalysts and monofunctional acid Ni–W oxide/Al2O3–USY

“…Recently, the bifunctional catalysts 1,7,8,10,[12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] has been used in the ring opening of naphthenes which showed good performance because of its more acid sites and higher hydrogenation on metal sites. The studies about bifunctional catalysts mainly focused on some noble metal catalyst, 1,[8][9][10]12,[14][15][16][18][19][20][21][24][25][26][28][29][30][31] which are easier sulfur poisoning. 7,32,33 It is reported that transition metal carbide catalysts have shown excellent hydrogenation activity for hydrodenitrogenation (HDN) and hydrodesulfurization (HDS) due to its higher hydrogenation on transition metal sites.…”

“…Also, the Ni-W oxide catalysts (Ni-W oxide/Al 2 O 3 -USY) were also studied for comparison. According to the previous works, 6,24 Ni-W carbide/Al 2 O 3 -USY was named as bifunctional catalysts and Ni-W oxide/Al 2 O 3 -USY was named as monofunctional acid catalysts. Decalin was chosen as the model reactant for the ring opening of naphthenes and hydrogenation.…”

Influence of rhodium content on the behavior of Rh/SiO2–Al2O3catalysts for selective ring opening of decalin

“…These rings are then more easily hydrogenated over the metallic sites. 61,62 As a consequence, the present results can be explained considering that the metallic activity (hydrogenolysis) and the acid activity follow opposite tendencies regarding Rh content. The metal activity rises at increasing Rh loads (Table 1) but at the expense of the acid sites (Table 3 and Fig.…”

Ru‐Pt catalysts supported on Al2O3 and SiO2─Al2O3 for the selective ring opening of naphthenes

“…On the other hand, the bifunctional ring opening mechanism assumes that the acid‐controlled ring contraction occurs first and that the ring opening follows, catalyzed by the metal sites with hydrogenolytic activity. These rings are then hydrogenated over the metal sites . The optimum catalyst should have high acidity, mainly of the Brønsted type, and hydrogenolytic activity.…”