Trace Pt Clusters Dispersed on SAPO‐11 Promoting the Synergy of Metal Sites with Acid Sites for High‐Effective Hydroisomerization of n‐Alkanes

Abstract

The significant increase of catalytic efficiency while remaining low Pt usage is constantly pursued, but remains a challenge. Here, a “vacuum‐assisted” (VA) process toward Pt clusters dispersed on SAPO‐11 (S‐11) is shown for a high‐effective hydroisomerization of n‐C16. The VA can make effective trapping of the Pt precursor on S‐11 due to intensive capillary action, being conductive to stabilize and disperse Pt cluster (≈1 nm) on S‐11 (V‐Pt/S‐11) for promoting synergy of Pt sites and acid sites on S‐11. The test indicates excellent catalytic activity and stability of trace Pt clusters (0.15 wt%, even lower, 0.035 wt%) on S‐11 (≈94.4% isomer selectivity at 94.3% conversion), much superior to I‐0.15 wt% Pt/S‐11 from traditional impregnation routes (≈88% selectivity at 90% conversion) and ever reported catalysts. The V‐Pt/S‐11 is also superior for the hydroisomerization of catalytic diesel oil with a decrease of freezing point up to 40 °C after hydroisomerization. The superior performance is attributed to the exposure of high acid density due to little coverage of Pt cluster on S‐11, high dispersion of Pt leading to form more metal–acid bifunctional sites, and enhanced (de)hydrogenation ability of Pt clusters. All of them can promote the effective synergy of metal sites (Pt) and acid sites.

Mesoporous Ni–Cu/WOx/ZrO2 Catalyst with Highly Dispersed WOx Clusters: Efficient Catalysts for Selective Hydroisomerization of Isobutane to n-Butane

“…The isoalkane isomerization to n -alkanes includes the isoalkane dehydrogenation to isoalkenes over metal sites, the isoalkene skeletal rearrangement on acid sites, and the n -alkene hydrogenation to corresponding n -alkanes on metal sites in accordance with the similar results of n -alkanes hydroisomerization to isoalkanes. − The stable tertiary carbon ion skeletal rearranges to an unstable secondary carbon ion in the hydroisomerization . Therefore, the isobutane hydroisomerization to n -butane is difficult and a high temperature is usually required, which leads to a large number of hydrocracking products and deposited carbon.…”

Electronic Tuning of Ni by Mo Species for Highly Efficient Hydroisomerization of n-Alkanes Comparable to Pt-Based Catalysts

“…8,10,14 So, we have anchored Ni−Mo species on the S-11 support based on a vacuum-assisted strategy, which is verified to be effective in controlling the dispersion and size of metals on supports (Figure S1). 21 The X-ray diffraction (XRD) patterns prove the formation of pure S-11 (JCPDS No. 42-0428) (Figure S2).…”

“…18−20 We have verified highefficient hydroisomerization by anchoring a trace amount of Pt clusters on S-11. 21 However, from the viewpoint of cost and practicality, it is necessary to explore high-effective non-noblemetal catalysts comparable to the Pt-based system. 22−24 There are intensive attempts exploring transition-metalbased (TM-based) catalysts for the (de)hydrogenation process because of their low cost and high availability.…”

Ni-promoted MoS2 in hollow zeolite nanoreactors: enhanced catalytic activity and stability for deep hydrodesulfurization

“…The key points are the control of the interaction between the negatively charged anions and positively charged anions or the nanoconnement effect of zeolite pores to restrict the migration and aggregation of metals during the calcination process. [19][20][21] More recently, we reported a "surface curvature-conned synthesis" strategy to conne the growth of 2D NiMoS X by introducing greater strain with larger surface curvature of the supports. 22 The assynthesized ultrasmall NiMoS X nanoakes exhibit highly efficient deep HDS performance, with a k HDS value of DBT of 14.05 Â 10 À7 mol g À1 s À1 .…”

“…Efficient methods such as chemical vapor deposition, 14 exfoliation, 15 and chemical and electrochemical intercalation 16 have been successfully applied to the preparation of nanocatalysts. To date, we have developed methods such as assembly-immobilization 17,18 and vacuum-assistance 19 to construct small-sized molybdenum-/tungsten-based catalysts. The key points are the control of the interaction between the negatively charged anions and positively charged anions or the nanoconfinement effect of zeolite pores to restrict the migration and aggregation of metals during the calcination process.…”