Pt-Zn clusters encapsulated in hierarchical MFI zeolite for efficient propane dehydrogenation

Lu, Jinyang; Xu, Zhikang; Yue, Yuanyuan; Bao, Xiaojun; Lin, Minggui; Zhu, Haibo

doi:10.1016/j.cej.2024.149369

“…It is reported that the introduction of secondary larger (meso and/or macro) pores in the micropore zeolites is conducive to improving accessibility of reactants to active sites and enhancing the diffusion efficiency of products and byproducts that are larger than the micropores from the zeolite channels to outside space, leading to higher activity and longer catalyst lifetime. 24,25 To the best of our knowledge, no research has been done on propane dehydrogenation over hierarchical SSZ-13 zeolite supported vanadium-based catalysts until now.…”

Section: Introductionmentioning

confidence: 99%

“…High propane conversion and propylene selectivity could be maintained during the entire reaction process, but the limitation of mass transport and the formation of coke species in zeolite cages caused a low diffusion efficiency and fast deactivation of the catalysts. It is reported that the introduction of secondary larger (meso and/or macro) pores in the micropore zeolites is conducive to improving accessibility of reactants to active sites and enhancing the diffusion efficiency of products and byproducts that are larger than the micropores from the zeolite channels to outside space, leading to higher activity and longer catalyst lifetime. , To the best of our knowledge, no research has been done on propane dehydrogenation over hierarchical SSZ-13 zeolite supported vanadium-based catalysts until now.…”

Section: Introductionmentioning

confidence: 99%

Nano-Hierarchical SSZ-13-Supported Low-Polymerized VO_X as Highly Efficient Catalysts for Propane Dehydrogenation

Sun,

Zhu,

Zhang

et al. 2024

Ind. Eng. Chem. Res.

0

View full text Add to dashboard Cite

Supported vanadium oxide (VO X ) catalysts are promising candidates for propane dehydrogenation (PDH) due to their high catalytic activity, low cost, and environmentally benign characteristics. Herein, vanadium-based catalysts supported on hierarchical SSZ-13 zeolites with V loadings ranging from 1 to 12 wt % were prepared and evaluated in PDH reaction. The characterization results show that various kinds of VO X species are formed on the SSZ-13 zeolites, and the polymerization degree of VO X species continually increases with rising V loading. The 5V/ SSZ catalyst possessing abundant low-polymerized VO X species with a large ratio of active V 3+ and V 4+ exhibits superior catalytic activity with 19.6% propane conversion and 91.3% propylene selectivity as well as good regeneration stability. The nanohierarchical structure of SSZ-13 zeolite is also found to play an important role in enhancing PDH activity due to the suppressed coke deposition, improved mass transfer, and enhanced accessibility of propane molecules to the active sites.

show abstract

Propane Dehydrogenation on Pt_xZn_y Active Sites in Silicalite‐1

Liu,

Bhowmick,

Liu

et al. 2024

Angewandte Chemie

0

View full text Add to dashboard Cite

The improvement of Pt‐based catalysts for propane dehydrogenation (PDH) has progressed by recent investigations that have identified Zn as a promising promoter for Pt subnanometer catalysts. It is desirable to gain insights into the structure, stability, and activity of such active sites and the factors that influence them, such as Zn:Pt ratio, Pt coordination and nuclearity. Here, we employ density functional theory and microkinetic simulations to investigate the stability of PtxZny (x=1‐3, y=0‐3) active sites grafted on silanols of Silicalite‐1 and the PDH activity of Pt. We find that the coordination of a Pt atom to a nest of grafted Zn(II) atoms increases the stability of the Pt1Zny sites, whose activity is similar for y=0‐2 and drops dramatically for y>2. We further demonstrate, via linear scaling relations and microkinetic simulations, that the turnover frequency obeys a volcano law as a function of propylene binding strength. The Pt2Zn1 and Pt3Zn1 sites are stable and exhibit activity similar to Pt1Zn2, but only Pt1Zn2 manifests reaction kinetics consistent with experimental data, strongly suggesting the active site composition in the synthesized catalyst samples. The methodology presented here suggests a general strategy for deducing active site information such as composition through simple kinetic experiments.

show abstract

Propane Dehydrogenation on Pt_xZn_y Active Sites in Silicalite‐1

Liu,

Bhowmick,

Liu

et al. 2024

Angew Chem Int Ed

0

View full text Add to dashboard Cite

The improvement of Pt‐based catalysts for propane dehydrogenation (PDH) has progressed by recent investigations that have identified Zn as a promising promoter for Pt subnanometer catalysts. It is desirable to gain insights into the structure, stability, and activity of such active sites and the factors that influence them, such as Zn:Pt ratio, Pt coordination and nuclearity. Here, we employ density functional theory and microkinetic simulations to investigate the stability of PtxZny (x=1‐3, y=0‐3) active sites grafted on silanols of Silicalite‐1 and the PDH activity of Pt. We find that the coordination of a Pt atom to a nest of grafted Zn(II) atoms increases the stability of the Pt1Zny sites, whose activity is similar for y=0‐2 and drops dramatically for y>2. We further demonstrate, via linear scaling relations and microkinetic simulations, that the turnover frequency obeys a volcano law as a function of propylene binding strength. The Pt2Zn1 and Pt3Zn1 sites are stable and exhibit activity similar to Pt1Zn2, but only Pt1Zn2 manifests reaction kinetics consistent with experimental data, strongly suggesting the active site composition in the synthesized catalyst samples. The methodology presented here suggests a general strategy for deducing active site information such as composition through simple kinetic experiments.

show abstract

Pt-Zn clusters encapsulated in hierarchical MFI zeolite for efficient propane dehydrogenation

Cited by 8 publications

References 43 publications

Nano-Hierarchical SSZ-13-Supported Low-Polymerized VO_X as Highly Efficient Catalysts for Propane Dehydrogenation

Nano-Hierarchical SSZ-13-Supported Low-Polymerized VO_X as Highly Efficient Catalysts for Propane Dehydrogenation

Propane Dehydrogenation on Pt_xZn_y Active Sites in Silicalite‐1

Propane Dehydrogenation on Pt_xZn_y Active Sites in Silicalite‐1

Contact Info

Product

Resources

About

Pt-Zn clusters encapsulated in hierarchical MFI zeolite for efficient propane dehydrogenation

Cited by 8 publications

References 43 publications

Nano-Hierarchical SSZ-13-Supported Low-Polymerized VOX as Highly Efficient Catalysts for Propane Dehydrogenation

Nano-Hierarchical SSZ-13-Supported Low-Polymerized VOX as Highly Efficient Catalysts for Propane Dehydrogenation

Propane Dehydrogenation on PtxZny Active Sites in Silicalite‐1

Propane Dehydrogenation on PtxZny Active Sites in Silicalite‐1

Contact Info

Product

Resources

About

Nano-Hierarchical SSZ-13-Supported Low-Polymerized VO_X as Highly Efficient Catalysts for Propane Dehydrogenation

Nano-Hierarchical SSZ-13-Supported Low-Polymerized VO_X as Highly Efficient Catalysts for Propane Dehydrogenation

Propane Dehydrogenation on Pt_xZn_y Active Sites in Silicalite‐1

Propane Dehydrogenation on Pt_xZn_y Active Sites in Silicalite‐1