Ultrasound-assisted synthesis of nanosized hierarchical ZSM-5 and its catalytic performance as the support for heteropolyacid

Qin

et al. 2016

Ind. Eng. Chem. Res.

This paper presents a facile and economical route to synthesizing hierarchical porous ZSM-5 zeolite (HP-ZSM-5) by an ultrasound-assisted method as a long-life catalyst for the glycerol dehydration reaction, which is an important reaction for the sustainable production of acrolein from biobased glycerol. The systematic characterizations indicate that the HP-ZSM-5 catalyst possesses large intracrystal mesopores and abundant accessible acid sites. The ultrasonic treatment and violent stirring play a critical role in the synthesis process. Compared with commercial ZSM-5 zeolite (C-ZSM-5), the turnover-frequency value at time zero of the HP-ZSM-5 catalyst increased nearly 1 times, and the lifetime of the HP-ZSM-5 catalyst was prolonged 9 times. The HP-ZSM-5 catalyst exhibits a slower coking rate with higher coke tolerance, the coke preferentially form inside the intracrystal mesopores, and the ratio of hardly removed graphitic carbon is lower than that of C-ZSM-5. The HP-ZSM-5 catalyst exhibits prominent stability of nearly 50 h and a high acrolein selectivity of 82%.

Section: Resultsmentioning

confidence: 99%

Hierarchical ZSM-5 Zeolite Synthesized by an Ultrasound-Assisted Method as a Long-Life Catalyst for Dehydration of Glycerol to Acrolein

Qin

et al. 2016

Ind. Eng. Chem. Res.

“…Among the supports that have been mentioned in different papers are: salts of heteropolyacids [6,7], Electronic supplementary material The online version of this article (doi:10.1007/s10934-015-0072-0) contains supplementary material, which is available to authorized users. zeolites [8], mesoporous silica [9][10][11], titania [12,13], active carbon [14,15], polymeric materials [16,17] and different molecular sieves: MCM-41, SBA-15, SBA-3, HMS [18][19][20][21][22][23][24][25][26][27][28]. Mesoporous molecular sieves such as SBA-15, highly stable and with better textural properties compared to other supports seem to be suitable for depositing HPA.…”

Section: Introductionmentioning

confidence: 99%

Acidic nickel salts of Keggin type heteropolyacids supported on SBA-15 mesoporous silica

et al. 2015

A series of heteropolyacids-mesoporous silica composites were prepared from nickel salt of molybdophosphoric acid Ni 1 HPMo 12 O 40 (NiHPM) by supporting on SBA-15 mesoporous silica in different concentrations of active phase. The structure and texture of these NiHPM/ SBA-15 composites were studied by XRD, FT-IR and micro-Raman spectroscopy, nitrogen physisorption at 77 K, UV-Vis-DRS and SEM-EDX. The effect of the support on thermal stability was investigated by TG-DTG, DTA and DSC methods. By impregnation of Ni salt on mesoporous silica the thermal stability of the Keggin structure increases in comparison with its parent bulk heteropolyacid. From XRD at small angles could be observed that NiHPM/SBA-15 composites with low surface coverage preserve the mesopore structure of silica, with well dispersed NiHPM on the surface of the pore walls for SBA-15. The adsorption of ammonia and its temperature programmed desorption using thermogravimetry were studied for acidity evaluation. The total acidity of the weak and strong acidic sites of NiHPM/SBA-15 composites is obviously increases in comparison with bulk Ni salt. The main products observed in the evolved gases during desorption of NH 3 were NH 3 , CO 2 and NO/ NO 2 .

“…The distance between the bands at ν = 811 and 795 cm −1 was too close, so they were combined smoothly into a bigger peak. Therefore, the Keggin structure of PTA was preserved in the catalyst without damage 36 .…”

Section: Resultsmentioning

confidence: 99%

Hydrocracking of Jatropha Oil over non-sulfided PTA-NiMo/ZSM-5 Catalyst

Yang

Liu

Fan

et al. 2017

Sci Rep

The PTA-NiMo/ZSM-5 catalyst impregnated with phosphotungstic acid (PTA) was designed for the transformation of Jatropha oil into benzene, toluene, and xylenes (BTX) aromatics. The produced catalyst was characterized by N2 adsorption-desorption, powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS), and the temperature-programmed desorption of ammonia (NH3-TPD). The catalytic performance was evaluated by gas chromatography (GC). The liquid products were 70 wt% of the feed oil, and the majority of the liquid products were BTX. The aromatization activity of the catalyst was improved by the addition of PTA and the hierarchical process. The favorable PTA amount was 20 wt% and the yield of BTX was 59 wt% at 380 °C, 3 MPa, H2/oil (v/v) = 1000 and LHSV = 1 h−1 over the PTA20-NiMo/HZ0.5 catalyst (PTA 20 wt%) without sulfurization.