Study of alumino-platinum-lithium catalysts during dehydrogenation of n-decane using the pulse method

n-decane dehydrogenation on bimetallic PtSn and PtGe catalysts prepared by dip-coating

“…This low acidic character of the support would be responsible for the low amount of cracking products. Besides, it must be indicated that Sn or Ge has a poisoning effect on the acidity of the support, mainly Sn [8,9,48]. It must be noted that the PtSn catalysts have a lower selectivity than PtGe ones, probably due to the different capacity of both metals to poison the acidic sites.…”

“…For this purpose the catalyst must con tain a dehydrogenating function, which is given by a noble metal (in our case Pt), though this component has hydrogenolytic properties, undesirable lateral process. In order to inhibit the hydrogenolytic capac ity of the noble metals, an inactive second metal com ponent, such as Sn or Ge, is added [5][6][7][8][9][10][11], to enhance the selectivity to olefins. γ A/α A (layers of γ Al 2 O 3 deposited on the periphery of the α Al 2 O 3 nucleus) was used as a support.…”

“…It is known that γ Al 2 O 3 has acidic sites which catalyze the undesirable lateral reac tions like cracking, isomerization and polymerization. The metallic function is responsible for the dehydro genation capacity, while aromatization takes place through a bi functional mechanism [8]. In this type of catalyst an acidic alumina has been used, but with the simultaneous addition of an alkaline metal (like Li) to poison the acidic sites so as to decrease the cracking capacity [8] and enhance the selectivity to olefins.…”

n-Decane dehydrogenation on Pt, PtSn and PtGe supported on spinels prepared by different methods of synthesis

“…This reaction is normally accompanied by undesirable side ones such as hydrogenolysis, cracking, aromatization and coke formation. In consequence, it is very important to analyze the addition of modifiers (elements of the Group 14 like Sn and Ge), which can affect the activity, selectivity and stability of the catalysts [3][4][5][6][7][8][9][10]. Furthermore the coke deposition can be diminished by using H 2 in the feed [11].…”