Post-synthesis alumination of MCM-41: Effect of the acidity on the HDS activity of supported Pd catalysts

Venezia, Anna Maria; Murania, R.; Parola, Valeria La; Pawelec, B.; Fierro, J.L.G.

doi:10.1016/j.apcata.2010.06.001

Cited by 43 publications

(31 citation statements)

References 27 publications

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“…35 A similar result was also reported for the incorporation of Al onto SBA-15, in which the Brönsted acid was generated in the aluminosilicate samples. 36 Moreover, the amount of extra-framework Al increased, as indicated by NMR data; therefore, this also contributed to the reduced number of acid sites. 3B.…”

Section: Nmr Analysismentioning

confidence: 95%

“…Comparing all the Al-MSNs, 10Al-MSN displayed the highest adsorption (79%), followed by 5Al-MSN (58%) and 1Al-MSN (35%). 36 The strength of the interaction between drugs and the silica surface is always variable and dependent on the adsorption active sites. 8 In contrast, herein the higher the Al loading, the higher the adsorptivity of the Al-MSNs toward ibuprofen.…”

Section: Adsorption Of Ibuprofenmentioning

confidence: 99%

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Elucidation of acid strength effect on ibuprofen adsorption and release by aluminated mesoporous silica nanoparticles

et al. 2015

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Mesoporous silica nanoparticles (MSN) with 1-10 wt% loading of aluminum (Al) were prepared and characterized by XRD, N 2 physisorption, 29 Si and 27 Al NMR, FT-IR and FT-IR preadsorbed pyridine. All samples were evaluated for ibuprofen adsorption and release. The results showed that MSN gave almost complete ibuprofen adsorption while the addition of 1, 5, and 10 wt% Al onto MSN (1Al-MSN, 5Al-MSN and 10Al-MSN) resulted in 35%, 58%, and 79% of adsorption, respectively. The characterization results elucidated that the highest adsorptivity of MSN was due to its highest surface silanol groups, while the increase in Brönsted acidity upon loading of Al provided more adsorption sites for the higher activity. Regardless of its highest adsorption capacity, MSN demonstrated the highest and fastest release ($100%)in 10 h, followed by 1Al-MSN, 5Al-MSN and 10Al-MSN. The increase in Al loading increased the acid sites that hold the ibuprofen molecules, which raised the retention in ibuprofen release. The pK a of Si-OH-Al that is lower than Si-OH sites also attracted the ibuprofen more strongly, which resulted in the slower release of Al-MSN as compared to MSN. The cytotoxicity study exhibited that ibuprofen loaded Al-MSN was able to reduce the toxicity in the WRL-68 cells, verifying its ability to hold and slow the release of ibuprofen as well as minimize the risk of drug overdose.

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Section: Nmr Analysismentioning

confidence: 95%

Section: Adsorption Of Ibuprofenmentioning

confidence: 99%

Elucidation of acid strength effect on ibuprofen adsorption and release by aluminated mesoporous silica nanoparticles

et al. 2015

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“…In particular, several groups have reported the preparation of palladium-containing MCM-41, by the modification of molecular sieves via post-synthesis impregnation. [23][24][25][26][27][28] Inclusion of the metal during the synthesis of the molecular sieve is less common, especially for the metal palladium. The major difference between the impregnation method and our approach is that the Au, Pd and Au-Pd nanoparticles are formed before and after formation of the mesoporous structure, respectively.…”

Section: Introductionmentioning

confidence: 99%

Versatile and efficient catalysts for energy and environmental processes: Mesoporous silica containing Au, Pd and Au-Pd

Silva

Fajardo

Balzer

et al. 2015

Journal of Power Sources

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We described a versatile approach for the synthesis of Au/MCM-41, Pd/MCM-41 and Au-Pd/MCM-41 by the direct incorporation of the noble metals into the MCM-41 framework. The structural, textural and chemical properties were characterized by X-ray diffraction (XRD), temperature-programmed reduction (TPR), N 2 -adsorption (BET and BJH methods), H 2 -chemisorption, small angle X-ray scattering (SAXS), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS). The nanomaterials, being comprised of Au, Pd and Au-Pd nanoparticles and possessing high surface areas were applied as versatile and efficient catalysts in benzene, toluene and o-xylene (BTX) oxidation and in the steam reforming of ethanol for hydrogen production. The results revealed that the catalytic behavior in both processes was influenced by the experimental conditions and the nature of the catalyst employed.The Au-Pd/MCM-41 catalyst was the most active in the BTX total oxidation. On the basis of characterization data, it was proposed that the close contact between Pd and Au and the higher dispersion of Pd may be responsible for the enhanced activity of the bimetallic catalyst. However, the strong interaction between the noble metals did not improve the performance of the bimetallic catalyst in ethanol steam reforming, the Pd/MCM-41 catalyst being the most active and selective for hydrogen production.

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“…Nevertheless, a major drawback in their use is their limited lifetime due to the easy poisoning of the active sites by sulfur [5][6][7]. Appropriate choice of the support and/or alloying with another metal is possible ways for increasing the sulfur tolerance [8][9][10]. Bimetallic systems such as Au-Pd, Au-Pt, and Pd-Pt catalysts, used in hydrodesulfurization and hydrogenation reactions, exhibit enhanced activity and longer lifetime as compared to the monometallic palladium and platinum catalysts [11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Structure control of silica-supported mono and bimetallic Au–Pt catalysts via mercapto capping synthesis

Parola

Kantcheva

Milanova

et al. 2013

Journal of Catalysis

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a b s t r a c tSiO 2 -supported monometallic and bimetallic platinum-gold catalysts are prepared by deposition of metal nanoparticles stabilized by mercaptopropyltriethoxysilane (MPTES) after different aging time of the solution containing metal ions and MPTES. The materials are tested in the hydrodesulfurization (HDS) reaction of thiophene and compared with corresponding catalysts prepared by the conventional deposition-precipitation (DP) method. The monometallic Pt and the bimetallic Au-Pt prepared by DP have comparable activity. With respect to the platinum catalyst prepared by DP, the corresponding platinum catalyst prepared by MPTES particle stabilization exhibits a substantial enhancement of the activity regardless the solution aging time. On the contrary, the MPTES-assisted Au-Pt catalysts have different activities, depending on the solution aging time, with the most active being the one obtained with the 5-day-aged solution. In accord with XRD, XPS, and FTIR, the aging time of the solution, through the different interaction of Pt or Au precursors with the mercapto groups, has a crucial effect on the structure and on the surface of the catalysts. The observed differences in the catalytic activity are related to the structural and compositional changes of the bimetallic particles.

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Post-synthesis alumination of MCM-41: Effect of the acidity on the HDS activity of supported Pd catalysts

Cited by 43 publications

References 27 publications

Elucidation of acid strength effect on ibuprofen adsorption and release by aluminated mesoporous silica nanoparticles

Elucidation of acid strength effect on ibuprofen adsorption and release by aluminated mesoporous silica nanoparticles

Versatile and efficient catalysts for energy and environmental processes: Mesoporous silica containing Au, Pd and Au-Pd

Structure control of silica-supported mono and bimetallic Au–Pt catalysts via mercapto capping synthesis

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