A DFT study on direct benzene hydroxylation catalyzed by framework Fe and Al sites in zeolites

The side-chain alkylation of toluene with methanol was investigated over some Fe-modified Cs ion-exchanged X zeolite (CsX) catalysts prepared via the impregnation method using different iron sources. The absorption/activation behaviors of the reactants on the surface of the catalysts were studied by in situ Fourier-transform infrared (FT-IR) spectroscopy and temperature programmed desorption (TPD) mass measurements. Modification of CsX with a small amount of FeCl3 could result in a considerable decrease in catalytic activity, due mainly to the remarkable decrease in the density of acidic and basic sites of the catalysts. Interestingly, the Fe(NO3)3-modified CsX with an optimum Fe loading of 0.15 wt.% shows improved catalytic activity and high yield compared to the side-chain alkylation products. Modification of CsX with Fe(NO3)3 could also result in a decrease in basic sites of the catalyst. However, such a change does not bring an obvious negative effect on the adsorption/activation of toluene, while it could effectively inhibit the generation of the undesired bidentate formate. Furthermore, the introduced FeOx species (derived from the decomposition of Fe(NO3)3) may also act as new Lewis acidic sites to participate in the activation of methanol and to stabilize the formed active intermediates (i.e., unidentate formate). Therefore, modification of CsX with a suitable amount of Fe(NO3)3 may adjust its adsorption/activation ability for reagents by changing the acid–base properties of the catalyst, which can finally enhance the catalytic performance for the side-chain alkylation of toluene with methanol.

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An efficient Fe2O3/HY catalyst for Friedel–Crafts acylation of m-xylene with benzoyl chloride

RSC Advances ◽

10.1039/c4ra04984e ◽

2014 ◽

Vol 4 (70) ◽

pp. 36951-36958 ◽

Cited By ~ 16

Author(s):

Manman Mu ◽

Ligong Chen ◽

Yunlong Liu ◽

Wangwang Fang ◽

Yang Li

Keyword(s):

Catalytic Activity ◽

Iron Oxide ◽

Benzoyl Chloride ◽

Catalytic Performance ◽

Reaction Parameters ◽

Hy Zeolite ◽

Lewis Acidic Sites ◽

Acidic Sites ◽

Excellent Catalytic Performance

Iron oxide supported on HY zeolite was prepared and exhibited excellent catalytic performance in the acylation of m-xylene with benzoyl chloride. It was characterized by XRD, BET, XPS, NH3-TPD and Py-IR. The catalytic activity of Fe2O3/HY is enhanced with the increase of Lewis acidic sites. Furthermore, the reaction parameters were optimized. Finally, the catalyst was easily separated reused for five runs without appreciable loss of catalytic activity.

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Catalytic hydrodeoxygenation of palmitic acid over a bifunctional Co-doped MoO2/CNTs catalyst: an insight into the promoting effect of cobalt

Catalysis Science & Technology ◽

10.1039/c5cy01575h ◽

2016 ◽

Vol 6 (7) ◽

pp. 2065-2076 ◽

Cited By ~ 37

Author(s):

Ranran Ding ◽

Yulong Wu ◽

Yu Chen ◽

Hao Chen ◽

Jianlong Wang ◽

...

Keyword(s):

Catalytic Activity ◽

Palmitic Acid ◽

Oxygen Vacancies ◽

Promoting Effect ◽

Lewis Acidic Sites ◽

Acidic Sites ◽

Lower Temperature ◽

Insight Into ◽

Co Doped

HDO of palmitic acid into C16 hydrocarbons was successfully achieved over Co doped MoO2/CNTs catalysts at a much lower temperature. Co could promote the formation of Lewis acidic sites, oxygen vacancies and Mo2C particles, which are all decisive factors for better catalytic activity.

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