Enhanced Sulfur Tolerance of Bimetallic PtPd/Al2O3 Catalysts for Hydrogenation of Tetralin by Addition of Fluorine

Abstract

A series of mono-and bi-metallic Pt-Pd/Al 2 O 3 samples with and without F were studied as aromatic hydrogenation catalysts. The effects of changing the order of impregnation of the Pt precursor and F as well as varying the calcination temperature (300-500°C) were investigated. Temperature programmed reduction (TPR) results demonstrate the presence of a higher fraction of dispersed metal precursor species left on the surface from the impregnation (PtO x Cl y ) on the Pt/Al 2 O 3 sample calcined at high temperature. The impregnation of F before the Pt precursor significantly decreases the interaction between the metal and the support. However, this decrease is not observed when F is impregnated after the metal precursor. For the bimetallic Pt-Pd catalysts, the sample prepared adding F before the metal show a higher degree of Pt-Pd interaction than either the parent Pt-Pd/Al 2 O 3 catalyst or the one prepared with F added later. TPD of ammonia result show the increase in strong acid sites when F is present. Activity tests for tetralin hydrogenation in the presence of 350 ppm dibenzothiophene indicate a better sulfur tolerance for all F-promoted catalysts, especially Pt-Pd.

Promotional Effect of Pd Addition on the Catalytic Activity of Composite Pt-Pd/AlSBA-15–β Catalyst for Enhanced n-Heptane Hydroisomerization

“…In line with the literature data, the incorporation of Cl − ions onto the various supports, either as part of the Pt precursor (incomplete decomposition of H 2 PtCl 6 ) or after chlorination may bring the Brønsted sites to appear [56][57][58]. Jongpatiwut et al [59] have observed that halogenation (in his work fluorination) of Pt-Pd/Al 2 O 3 strongly increases the acidity of the catalysts. D'Ippolito et al [60] have also observed an acidity enhancement in the case of Pd catalysts as an effect of Cl − ions added, either by the Pd chlorinated precursors and/or by the added HCl during metal impregnation.…”

Hydrogen from glycerol steam reforming with a platinum catalyst supported on a SiO 2 -C composite

“…In the region at 150 C, there is only H 2 consumption and the peak is attributed to Pt reduction. According to the literature, the lowest temperature peak can be assigned to the reduction of Pt oxide species weakly interacting with the support [46,47]. The signal at a higher temperature, 640 C, corresponds to the consumption of H 2 and the release of CO. For this reason, this peak is assigned to H 2 consumption by unsaturated sites and to the decomposition of the surface oxygenated groups of the C support.…”

High Catalytic Activity of Pt/Al2O3 Catalyst in CO Oxidation at Room Temperature—A New Insight into Strong Metal–Support Interactions

“…The authors of [26][27][28][29] assumed that the first peak can be attributed to the reduction of oxy-or hydroxychloride platinum species, while the high temperature peak can be attributed to the two-dimensional dispersive oxychlorinated platinum species, which strongly interact with the alumina support. It should be noted that the above conclusions are generally accepted.…”