Skeletal Reactions of n-Hexane over Pt-NaY, Pt/SiO2, Hy, and Mixed Pt/Sio2 + HY Catalysts

Pt supported on Zn modified silicalite-1 zeolite as a catalyst for n-hexane aromatization

“…In this work, the M f values are about 77.5, 35.9, 27.0 and 14.7 at the temperatures of 40 0, 450, 50 0 and 550 °C over Pt 0.1 -Zn 6.0 /S-1 catalyst, respectively. Taking into account that the value normally reported for an acidic catalyst is about 45 [46] , it is concluded that in our samples (Pt 0.1 -Zn 6.0 /S-1 catalyst) hydrogenolysis prevails on metal sites when the reaction temperature is above 400 °C. Since large Pt particles (observed in Fig.…”

“…The analysis of the product composition in the C 1 -C 5 cut may provide information about whether the hydrogenolysis or the hydrocracking prevails. Accordingly, a M f parameter ( (C 2 -C 5 )/C 1 ratio) is used in the literature to evaluate the metal or acidic behavior in cracking reactions [46] . In this work, the M f values are about 77.5, 35.9, 27.0 and 14.7 at the temperatures of 40 0, 450, 50 0 and 550 °C over Pt 0.1 -Zn 6.0 /S-1 catalyst, respectively.…”

Some Aspects of the Mechanisms of Catalytic Reforming Reactions

“…They can occupy appropriate sites in the framework of a zeolite support and anchor small Pt particles as [Pt n -H x ] x+ entities (Bai and Sachtler, 1991). These may represent peculiar bifunctional sites where the two functions are not separated in space, andsas Table 3 showssbifunctional aromatization can be more pronounced over the catalysts with the highest dispersion where such sites should be most abundant (Paa ´l et al, 1995). Increasing hydrogen pressure suppressed hexene formation rather than aromatization on this sample.…”

Effect of NaY Zeolite at Different Calcination Temperatures on the Activity in Hydroformylation of Formaldehyde

“…And this confine can be reduced after calcination at high temperature, and more rhodium species can be exposed to participate in the coordination reaction. [31] …”

“…Although the molecular diameter of triphenylphosphine is only 0.72 nm, it is difficult to form metal complexes with larger diameters with rhodium metal dispersed in the supercages or sodalite cages of zeolite, the special cages structure of zeolites would confine rhodium species so that only a small amount of rhodium can coordinate with PPh 3 . [30] And this confine can be reduced after calcination at high temperature, and more rhodium species can be exposed to participate in the coordination reaction.. [31] In an anionic (Scheme 1), a common starting compound HRh(CO) 2 (PPh 3 ) 2 first needs to be deprotonated to form [Rh(CO) 4-x (PPh 3 ) x ] À (x = 0 to 2), and then insert the RhÀ H bond with HCHO through nucleophilic addition to form an anionic rhodium complexes. The surface of synthetic NaY zeolite shows only weak Lewis acidity due to the presence of Na + and non-framework Al species in zeolites.…”