Naphthalene hydrogenation over Pt/TiO2–ZrO2 and the behavior of strong metal–support interaction (SMSI)

Abstract

Vapor-phase naphthalene hydrogenation over various supported Pt catalysts was studied in a continuous fixed-bed microreactor. Experimental results indicated that the catalytic activity of the catalyst strongly depended on the nature of the support and the pre-reduction temperature. Reaction order was independent of the support as the reaction was pseudo-first-order with respect to naphthalene in the temperature range studied. By comparing the apparent rate constant over various supported Pt catalysts, Pt supported on TiO 2 -ZrO 2 (1 : 1) reduced at a low temperature showed the highest activity. For higher pre-reduction temperatures, Pt/TiO 2 -ZrO 2 (1 : 1) exhibited the least suppression of H 2 uptake, due to a stabilization effect exerted by ZrO 2 , which prevents the migration of TiO x moieties and the blockage of the Pt surface. However, the apparent depression of the hydrogenation activity of high-temperature reduced Pt/TiO 2 -ZrO 2 (1 : 1) was significantly greater than the suppression of its hydrogen uptake. Furthermore, the decreasing value of the hydrogenation activity relative to the hydrogen uptake demonstrates electron perturbations between the support and the Pt metal.

Hydrodeoxygenation of Guaiacol on Ru Catalysts: Influence of TiO2–ZrO2 Composite Oxide Supports

“…Moreover, it could be the Ti 3+ species on the Ru particles’ surface that prevented the further oxidation of reduced Ru particles (Figure a). The result of higher CO chemisorption capacity for TiO 2 –ZrO 2 supported Ru catalysts is attributed to the presence of ZrO 2 in the composite oxides that partly prevent partially reduced Ti 3+ species from migrating onto the surface of Ru particles, which is in line with the conclusion drawn by Lu et al…”

“…Moreover, it could be the Ti 3+ species on the Ru particles' surface that prevented the further oxidation of reduced Ru particles (Figure 5a). The result of higher CO chemisorption capacity for TiO 2 −ZrO 2 supported Ru catalysts is attributed to the presence of ZrO 2 in the composite oxides that partly prevent partially reduced Ti 3+ species from migrating onto the surface of Ru particles, which is in line with the conclusion drawn by Lu et al 58 The number and strength of surface acidities on the catalysts are determined by microcalorimetric adsorption of NH 3 . Differential heat as the function of coverage for ammonia adsorption on catalysts is shown in Figure 6.…”

NiMo Supported on Faujasite‐modified Al2O3 as Catalysts for the Hydrotreatment of a Light Cycle Oil/Straight Run Gas Oil Mixture

“…The solids IA and IANex were also the most active in the HDA test, Figure 5. Some authors (Lu et al, 2000) have proposed that Lewis acid sites located on the support surface could provide additional sites for the adsorption of poly-aromatics molecules. Consequently, the aromatic ring saturation rate could be enhanced.…”

Study of Different Ti/Zr Ratios on the Physicochemical Properties and Catalytic Activities for CuO/Ti–Zr–O Composites

“…Lately, studies on the TiO 2 –ZrO 2 mixed oxides have attracted a wide interest because this system contains a larger Brunauer–Emmett–Teller specific surface area. − Further, ZrO 2 has an excellent redox nature and is easy to use to form pores and interact with active components. Huang et al .…”