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We prepared a series of highly dispersed tetrahedrally coordinated tungsten catalysts with different Si/Al ratios by a simple "top-down" method for catalytic cracking of 1-hexene to propene. High 1-hexene conversion (>97%) and propene selectivity (>40%) could be maintained at 575°C over the W-ZSM-5(60) catalyst. [Display omitted] • Stability of the Si-O-Al structure in the W-ZSM-5 framework was enhanced. • Active tetrahedrally coordinated W (VI) species were highly dispersed on ZSM-5 catalysts. • Superior propene selectivity was achieved over W-ZSM-5 (60) catalysts. • The mechanism of W-ZSM-5 on the 1-hexene cracking reaction path were clarified. Reasonable regulation of the acidity of ZSM-5 could fundamentally improve the catalytic performance for the cracking of low-carbon olefins to propene. Herein, a series of ZSM-5 catalysts with highly dispersed tetrahedrally coordinated W(VI) species were prepared for the catalytic cracking of 1-hexene to propene by a simple "top-down" method. Multi-characterizations revealed that the introduction of W enhanced the stability of the Si-O-Al structure in W-ZSM-5 by eliminating the non-skeleton aluminum and excessive Brønsted acid sites, leading to a superb resistance to carbon/coke deposition. Moreover, the Lewis acid sites originated from the active tetrahedrally coordinated W (VI) species improved the propene selectivity via inhibiting the polymerization of products. In addition, through the optimization of various parameters (such as Si/Al ratio, temperature and weight hourly space velocity), high 1-hexene conversion (>97%) and propene selectivity (>40%) could be maintained at 575 °C over the W-ZSM-5(60) catalyst during 30 h long period reaction. This work may provide some new insights for the effect of W-based catalysts on acid composition in the cracking of light olefins to propene. [ABSTRACT FROM AUTHOR]

Based on density functional theory (DFT) calculation and microkinetic analysis, metal single-atom-doped ZSM-5 zeolite catalysts for naphtha cracking are screened. The calculation results show that the strong electronic interaction between metal single atom and zeolite skeleton (especially Ag and Cu) could enhance structural stability. The volcanic diagram of turnover frequency shows that Ag and Cu doped ZSM-5 zeolite catalyst is at the top of the volcano, which is close to the best choice. [Display omitted] • Metal single-atom-doped ZSM-5 zeolite catalyst exhibits good structural stability. • The adsorption of naphtha hydrocarbon molecules and the activation of C–H bond are greatly promoted. • The binding energy of carbon and hydrogen can be used as a descriptor for the catalytic cracking of naphtha on M−ZSM−5. • Ag and Cu single-atom-doped ZSM-5 are predicted to exhibit excellent catalytic activity. • Mo and Pd single-atom-doped ZSM-5 display great potential in the enhancement of propylene selectivity. Metal doped ZSM-5 catalyst has attracted much attention due to its unique catalytic activity for C–H bond activation. In this work, based on density functional theory (DFT) calculations and microkinetic analysis, we prospectively explored the catalytic activity of 12 kinds of transition metals (M = Fe, Co, Ni, Cu, Mo, Ru, Rh, Pd, Ag, W, Pt, Au) single-atom-doped ZSM-5 zeolite catalysts in the catalytic cracking of naphtha. The results show that there is a strong electronic interaction between metal atom and ZSM-5 skeleton. This induced stable structure could improve the adsorption ability of hydrocarbon, thus promoting the activation of C–H bond and the cracking of carbenium ion. Moreover, C and H binding energy were identified as descriptors in describing catalytic activity via good scaling relations. The turnover frequency volcano diagram shows that the Ag and Cu doped ZSM-5 zeolite catalyst is close to the best choice. In addition, Pd and Mo are potential metal choices with good selectivity through selectivity analysis. This work has important guiding significance for understanding the fluid catalytic cracking (FCC) mechanism and designing high-efficiency cracking catalysts. [ABSTRACT FROM AUTHOR]