Study of the interaction between hydrogen and the MoO3–ZrO2 catalyst

Bifunctional mesoporous silica nanomaterials (MSN) with various Si/Al molar ratios of 7, 10, 20 and 50 in platinum supported (Pt/HAlMSN) were synthesized using sol-gel followed by post-synthesis methods. XRD and nitrogen sorption results confirmed the mesoporous structure with the surface areas of 537-775 m 2 g -1 . 27 Al NMR spectroscopy confirmed aluminium loading with tetrahedral, pentahedral and octahedral structures. Pyridine adsorbed IR results indicated that the aluminium incorporating led to generate strong Brønsted and Lewis acidic sites. Catalytic activity was investigated for cumene hydrocracking in a pulse microcatalytic reactor at the temperature range of 323-573 K which revealed that this activity depends on the number of Lewis and Brønsted sites. High yield of cumene conversion increased from Si/Al of 50 to 10 and decreased in Si/Al of 7 due to the presence of pentahedral Al and/or inactive tetrahedral Al atoms in Pt/HAlMSN-7. High selectivity of α-methylstyrene showed the important role of Lewis acid sites in these bifunctional catalysts. In spite of the coke formation in the Pt/HAlMSN catalysts, the reactivation recovered the activity of catalysts after 100 h of reaction. The molar coefficient absorbances of Pt/HAlMSN were measured using pyridine followed by water adsorption monitored by FTIR.

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“…A' 1490 = ɛ B1490 (X B + X' B ) + ɛ L1490 (X L +X' L ) (12) A' 1545 = ɛ 1545 (X B + X' B ) (13) From the Eq. (10) to Eq.…”

Section: Measurement Of Molar Absorption Coefficients Of the Pt/halmsmentioning

confidence: 99%

High activity of aluminated bifunctional mesoporous silica nanoparticles for cumene hydrocracking and measurement of molar absorption coefficient

et al. 2015

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“…The pure ZrO 2 catalyst hardly adsorbs or activates any hydrogen, so the hydrogenation activity of ZrO 2 is very limited . Some studies showed that doping of heteroatoms (e. g. Al, Ce, Zn, Mo and Pt) into ZrO 2 catalyst could significantly promote the adsorption and dissociation of H 2 . Pd supported on ZrO 2 was also used to hydrogenate CO to methanol .…”

Section: Introductionmentioning

confidence: 99%

Selective Conversion of Syngas to Aromatics over a Mo−ZrO₂/H‐ZSM‐5 Bifunctional Catalyst

et al. 2019

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Direct conversion of syngas to aromatics is an extremely challenging target due to the complex reaction pathways. Herein, we present a well‐designed bifunctional catalyst composed of Mo‐doped ZrO2 nanoparticles and zeolite H‐ZSM‐5 for one‐step conversion of syngas to aromatics. The Mo−ZrO2 converts syngas to methanol as reaction intermediate, which can be successively converted to aromatics by H‐ZSM‐5. Hydrogenation ability of mixed oxides is pivotal to both selectivity and productivity of aromatics. We intensively clarify the individual role of catalyst components among CO activation, H2 activation and aromatization. With a Mo/Zr molar ratio of 1 : 68, the Mo−ZrO2/H‐ZSM‐5 resulted in 76 % selectivity of aromatics at 22 % CO conversion, and the productivity of aromatics reached 0.17 g gcat−1 h−1 at 400 °C and 4 MPa. Moreover, the distribution of aromatics can be tuned by surface modification of H‐ZSM‐5.

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“…The Lewis acid site trapping an electron reacts with a second spiltover hydrogen to form an H À bound to a Lewis acid site [5,11]. The formation of protonic acid sites was monitored by IR spectroscopy, while the formation of electron was monitored by ESR spectroscopy [24,27]. Similar phenomenon was observed for MoO 3 -ZrO 2 in which the interaction of hydrogen with the surface catalyst formed protonic acid sites and electrons which led to change in the Mo oxidation state.…”

Section: Hydrogen Interactionmentioning

confidence: 63%

“…Heating in the presence of hydrogen, the absorbance band of acidic OH group at 1545 cm À1 was intensified indicating the formation of OH groups (Fig 5A), while the ESR signal at g = 1.93 corresponds to hexa-coordinated Mo 5+ species decreased due to the increase in the interaction of electrons and electron-deficient Mo 5+ cations (Fig. 7A inset) [24,40]. The changes were clearly seen in the Figs.…”

Section: Hydrogen Interactionmentioning

confidence: 89%

“…We have previously reported the acidic properties of MoO 3 -ZrO 2 , in relation to the active sites which participate in the formation of active protonic acid sites from molecular hydrogen that favor in nheptane isomerization [23,24]. Although it has also been reported widely that the introduction of Pt site is able to improve the activity and stability of zeolites, alumina, WO 3 -ZrO 2 , and SO 2À 4 -ZrO 2 , there is almost no report related to the study of Pt loaded on MoO 3 -ZrO 2 for hydroisomerization of alkanes in the literature.…”

Section: Introductionmentioning

confidence: 99%

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IR study of active sites for n-heptane isomerization over MoO3-ZrO2

Ruslan¹,

Fadzillah²,

Karim³

et al. 2011

Applied Catalysis A: General

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Study of the interaction between hydrogen and the MoO3–ZrO2 catalyst

Cited by 20 publications

References 30 publications

High activity of aluminated bifunctional mesoporous silica nanoparticles for cumene hydrocracking and measurement of molar absorption coefficient

High activity of aluminated bifunctional mesoporous silica nanoparticles for cumene hydrocracking and measurement of molar absorption coefficient

Selective Conversion of Syngas to Aromatics over a Mo−ZrO₂/H‐ZSM‐5 Bifunctional Catalyst

IR study of active sites for n-heptane isomerization over MoO3-ZrO2

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Study of the interaction between hydrogen and the MoO3–ZrO2 catalyst

Cited by 20 publications

References 30 publications

High activity of aluminated bifunctional mesoporous silica nanoparticles for cumene hydrocracking and measurement of molar absorption coefficient

High activity of aluminated bifunctional mesoporous silica nanoparticles for cumene hydrocracking and measurement of molar absorption coefficient

Selective Conversion of Syngas to Aromatics over a Mo−ZrO2/H‐ZSM‐5 Bifunctional Catalyst

IR study of active sites for n-heptane isomerization over MoO3-ZrO2

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Selective Conversion of Syngas to Aromatics over a Mo−ZrO₂/H‐ZSM‐5 Bifunctional Catalyst