Shape-selective catalysis by phosphate modified ZSM-5: Generation of new acid sites with pore narrowing

L, Janardhan H; Shanbhag, Ganapati V.; Halgeri, A. B.

doi:10.1016/j.apcata.2013.11.029

Cited by 68 publications

(62 citation statements)

References 23 publications

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“…This sets up the grounds for the Methanol-to-Propylene (MTP) process: carried out over mildly Brønsted acidic ZSM-5 catalysts at slightly higher temperatures than classical MTO chemistry (T ≥ 500 °C ). The improved propylene yields have been rationalized on the basis of the lower density of BAS and, in some cases, spatial constrains due to postsynthetic modifications, 14 however no clear structure-performance descriptors have been developed.…”

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confidence: 99%

Structure–performance descriptors and the role of Lewis acidity in the methanol-to-propylene process

et al. 2018

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mentioning

confidence: 99%

Structure–performance descriptors and the role of Lewis acidity in the methanol-to-propylene process

et al. 2018

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“…The SiO 2 /Al 2 O 3 ratio of the zeolites increased slightly aer the P and P/Ni modication. 34,46 XRD analysis result shows that modication with P and P/Ni does not affect the framework structure of ZSM-5. 29,34 In addition, it is noticed that although the P-ZSM-5 zeolite was impregnated with a lower P mass ratio (2 wt% P) during the incipient wetness treatment than the P/Ni-ZSM-5 zeolite (3 wt% P), they had a comparable actual P content aer they were calcinated for subsequent CFP tests (1.54 and 1.87 wt%, measured by XRF technique).…”

Section: Catalyst Characterizationsmentioning

confidence: 91%

“…This is probably because some soluble P species (e.g., orthophosphate monoester and pyrophosphate) on P-modied ZSM-5 zeolites would be washed off the zeolites during their subsequent Ni impregnation to obtain P/Ni-ZSM-5 zeolites. This result suggests that P species has penetrated into the channels of ZSM-5 during P impregnation, 46 which would decrease the low-angle XRD intensities of ZSM-5. All samples exhibit the characteristic peaks of MFI type zeolite at $8 and 23 (see Fig.…”

Section: Catalyst Characterizationsmentioning

confidence: 99%

“…3), suggesting a decrease in the strength of Brönsted acidity. 28,46,52 On the other hand, Ni impregnation would increase the Lewis acid sites of zeolites due to the deposition of nickel species at the external surface of ZSM-5, but decrease the strong Brönsted acidity due to replacement of some protons by nickel ions. The result shows that the density of Brönsted acid sites on ZSM-5 decreased considerably aer the zeolite was impregnated with P, and further decreased with Ni impregnation (Table 1).…”

Section: Catalyst Characterizationsmentioning

confidence: 99%

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Thermally stable phosphorus and nickel modified ZSM-5 zeolites for catalytic co-pyrolysis of biomass and plastics

Yao

Feng

et al. 2015

RSC Adv.

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A series of phosphorus (P) and phosphorus/nickel (P/Ni) modified ZSM-5 zeolites were prepared by impregnation of a conventional ZSM-5 zeolite with P and subsequent Ni. The conventional, P-, and P/Ni-modified ZSM-5 zeolites were then tested as the catalysts for petrochemical production from cofeed catalytic fast pyrolysis (CFP) of pine wood and low-density polyethylene (LDPE) mixtures. Results showed that the yield of valuable petrochemicals (olefins and aromatic hydrocarbons) from co-feed CFP increased from 42.9 C% for conventional ZSM-5 to 52.8-54.1 C% for P-and P/Ni-modified ZSM-5, while the yields of low-value alkanes and undesired char/coke decreased from 17.3 C% and 22.6 C% to 9.6-10.2 C% and 18.9-15.7 C%, respectively. ZSM-5 impregnation with P and P/Ni thus significantly improved the product distribution in co-feed CFP of biomass and LDPE. In addition, modification with P and P/Ni improved considerably the hydrothermal stability of zeolites to resist steam-induced catalyst deactivation that may occur in co-feed CFP. When the conventional ZSM-5 zeolite was pretreated with 100% steam at 550 C for 3-9 h, it produced 26.7-32.1% lower aromatic yields than untreated ZSM-5 in co-feed CFP. In contrast, steam pretreatment did not considerably affect the activity of P-and P/Ni-ZSM-5 zeolites for aromatic production. They maintained comparable aromatic yields in co-feed CFP when they had been steam pretreated for up to 9 h. These results indicate that ZSM-5 modification with P and P/Ni may provide a viable way to improve the catalyst's activity and life time for petrochemical production from co-feed CFP of biomass and plastics.

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“…However, a variety of modification techniques are the key factor to improve the shape-selectivity of molecular sieve and catalytic activity [17,18]. Tungsten has received considerable attention due to its unique physical-chemical properties [19].…”

Section: Introductionmentioning

confidence: 99%

Synthesis and application of different phthalocyanine molecular sieve catalyst for oxidative desulfurization

Zhao

Wang

et al. 2015

Journal of Solid State Chemistry

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Shape-selective catalysis by phosphate modified ZSM-5: Generation of new acid sites with pore narrowing

Cited by 68 publications

References 23 publications

Structure–performance descriptors and the role of Lewis acidity in the methanol-to-propylene process

Structure–performance descriptors and the role of Lewis acidity in the methanol-to-propylene process

Thermally stable phosphorus and nickel modified ZSM-5 zeolites for catalytic co-pyrolysis of biomass and plastics

Synthesis and application of different phthalocyanine molecular sieve catalyst for oxidative desulfurization

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