Synthesis of mesoporous Pt@SAPO-11 via in situ encapsulation for the decarboxylation of oleic acid to prepare C8–C17 alkanes

Abstract

A series of mesoporous Pt@SAPO−11 catalysts with different Pt loadings were prepared using an in situ encapsulation process. These materials exhibited good topological structures and high Brunauer−Emmett−Teller (BET) surface areas...

Synthesis of mesoporous Pt@KIT−6/SAPO−11 VIA in situ encapsulation to catalyze the decarboxylation of oleic acid to C8–C17 alkanes

“…In the present study, the weak characteristic Pt peaks observed in the XRD patterns can also be partly ascribed to the low Pt concentrations in these materials. The wide-angle XRD patterns obtained from the Pt@KIT−6/SAPO−11 catalysts were like those generated by the Pt@SAPO−11 specimens prepared by Liu et al, 21 meaning that the characteristic peaks related to SAPO−11 and the AEL structure also appeared. In addition, the present patterns exhibit obvious characteristic Pt peaks.…”

“…In the present work, the catalyst with a SiO 2 :Al 2 O 3 molar ratio of 0.4 and a Pt loading of 0.8 showed the best catalytic performance and produced a yield of C8-C17 alkanes as high as 85.1%. This value was superior to the yield of 80.8% obtained using Pt@SAPO−11 prepared via in situ encapsulation 21 under the optimal conditions. This behaviour was attributed to the suitable mesoporous structure of this material, as well as its physical and chemical properties.…”

“…The pore size distributions of these materials also show a single peak, and the pore sizes are concentrated in the range of 7–10 nm. The BET surface areas of the Pt@KIT−6/SAPO−11 specimens were in the range of 138–197 m 2 /g (Table 2), so they were larger than those of Pt@SAPO−11, 21 indicating that using KIT−6 as the silicon source increased the specific surface area of the composite molecular sieve catalyst. As the Pt loading was increased from 0.4 to 1.2 wt%, the BET surface areas decreased; meanwhile, the average pore sizes increased (Table 2) as more Pt entered the pores and smaller pores were blocked.…”

“…Under the same reaction conditions, the conversion obtained from the former material was 13.2% higher than that of the latter. In previous work by our own group, 21 mesoporous Pt@SAPO−11 was prepared via an in situ synthesis process and used for the decarboxylation of oleic acid under a CO 2 atmosphere. Following a 4 h reaction at 340 °C, a C8 − C17 alkanes yield of 80.8% was obtained from this catalyst.…”

Hydroisomerization of 1-octene utilizing hierarchical SAPO-11-supported Ni catalysts: effect of the alkyl chain length of the mesoporogen

“…Actually, long-chain alkyl trimethyl ammonium bromides (C n H 2 n +1 (CH 3 ) 3 NBr) are often used as mesoporogens in the synthesis of hierarchical SAPO-11 molecular sieves. 5,13,25,27,38–40 Unfortunately, how the alkyl chain length of the mesoporogen affects the physicochemical properties and catalytic performance of hierarchical SAPO-11 molecular sieves has not been systematically investigated. In this study, hierarchical SAPO-11 molecular sieves will be synthesized by using n -alkyltrimethylammonium bromides with different alkyl chain lengths from C 8 to C 16 as mesoporogens and analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), N 2 adsorption–desorption, transmission electron microscopy (TEM), NH 3 temperature-programmed desorption (NH 3 -TPD) and pyridine adsorption Fourier-transform infrared (Py-IR).…”