Hydrogenation of Tetralin over Supported Ni and Ir Catalysts

Abstract

Selective hydrogenation and ring opening (SRO) of tetrahydronaphthalene (tetralin) was studied over nickel and iridium supported catalysts in the context of the removal of polynuclear aromatics from diesel fuel. The tetralin hydrogenation was carried out in a fixed-bed reactor at 270°C, using H2pressure of 30 bars, WHSV of 2.3 h−1, and H2/feed molar ratio of 40; the resultant products were analyzed by GC and GC-MS. The Ir/SiO2catalyst gave 85% of tetralin conversion and 75.1% of decalin products selectivity whereas Ni/SiO2catalyst showed an unprecedented high catalytic performance with 88.3% of tetralin conversion and 93% of decalin products selectivity. The catalysts were characterized by using different characterization techniques such as XRD, TPR, and HR-TEM to know the physicochemical properties as well as active sites in the catalysts.

Direct Amination of Dodecanol over Noble and Transition Metal Supported Silica Catalysts

“…The 2 wt % Ru/SiO 2 catalyst exhibited the lowest reduction temperature in the interval between 140 and 160 °C, in accordance with the literature . The 2 wt % Ir/SiO 2 catalyst exhibited the reduction temperature in the range of 160–225 °C (Figure ), also in line with the value reported . For this catalyst a low reduction temperature can be explained by high metal dispersion (60% according to TEM) .…”

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.…”

Tetralin Hydrogenation over Supported Nickel Catalysts

“…The characteristic properties of LCO show a high content of sulfur, nitrogen, and polyaromatic compounds (mostly diaromatic compounds). Therefore, hydrogenating multiring aromatics will result in a better diesel fuel blend that has a higher cetane number. − Similarly, jet fuel is also affected by the aromatic content, which reduces the thermal stability of the blend. It has been reported in literature that hydrogenated multiring products play an important role in improving the thermal stability and also in preventing thermal degradation and the solid-forming tendency of long-chain alkanes in the fuel blend …”

“…Based on the aforementioned aspects, the enhancement of this process has increased substantially in recent years, where several catalysts have been developed to boost the catalytic activity and selectivity of naphthalene and tetralin hydrogenation under moderate reaction conditions. Several studies have been conducted with the aim of studying the effects of altering the catalyst preparation methods and materials (e.g., supports and active metal) on the hydrogenation reaction, while other studies focused on investigating the influence of operating conditions and the effect of feed poisoning on the catalytic integrity and stability. ,,, It was inferred from these studies that the hydrogenation reaction was greatly influenced by varying the preparation techniques and the starting materials of the catalysts. This suggested that the change in the physicochemical properties of the catalysts can improve the catalytic activity and reliability.…”