Screening of optimum condition for combined modification of ultra-stable Y zeolites using multi-hydroxyl carboxylic acid and phosphate

Chang, Xing-wen; He, Lei; Liang, Hao; Liu, Xinmei; Zhang, Yan

doi:10.1016/j.cattod.2010.02.009

Cited by 28 publications

(13 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These are the framework structure types containing D4R units and the corresponding type materials which have been obtained by the ITQ synthesis group where the fl uoride route was developed: ISV (ITQ-7) [ 110 ], ITW (ITQ-12) [ 12 ], ITH (ITQ-13) [ 13 ], BEC (beta polymorph C or ITQ-17) [ 36 ], IWW (ITQ-22) [ 11 ], IWR (ITQ-24) [ 11 ], IWS (ITQ-26) [ 12 ], IWV (ITQ-27) [ 111 ], ITR (ITQ-34) [ 14 ], -ITV (ITQ-37) [ 112 ], and IRR (ITQ-44) [ 113 ]. In addition, the all-silica LTA (ITQ-29) [ 114 ] was also obtained using fl uoride as one of the structure directors.…”

Section: The Clathrasil Octadecasil and The F Synthesis Of Zeolitesmentioning

confidence: 99%

Structure Analysis in Zeolite Research: From Framework Topologies to Functional Properties

Gies

Marler

2016

Green Chemistry and Sustainable Technology

View full text Add to dashboard Cite

The solution and the refi nement of crystal structures of microporous materials are of prime interest for the synthesis and application community in porous solid research. The structure of a material reveals not only the geometry of the bonding network of the rigid framework but also the location of the nonframework constituents responsible for the porosity of the material. Analyzing the structure, therefore, unveils the synthesis protocol including nucleation and growth. The properties related to the porous net correspond to the local structure, i.e., the composition and the geometry of local confi gurations. It thus inspires ideas about possible properties and modifi cations to improve functionality.The chapter is intended to highlight the contribution of crystallographic analysis of microporous materials and in particular porous silicates to the success of this class of materials. It does not survey the continuous growth of materials in the fi eld but show how the insight gained from crystallographic studies acted as catalyst in the further development of the fi eld.

show abstract

Section: The Clathrasil Octadecasil and The F Synthesis Of Zeolitesmentioning

confidence: 99%

Structure Analysis in Zeolite Research: From Framework Topologies to Functional Properties

Gies

Marler

2016

Green Chemistry and Sustainable Technology

View full text Add to dashboard Cite

show abstract

“…In contrast, desilication of Y zeolite by alkali can generate enough defects and rich mesoporosity in inner zeolite [20]. Various acid and basic agents such as phosphoric acid, citric acid, ammonium fluorosilicate and NaOH have been adopted to modify Y and ZSM-5 zeolites in our previous studies [21][22][23][24]. However, one obvious drawback of posttreatment is the great reduction of crystallinity which decreases the structural stability.…”

Section: Introductionmentioning

confidence: 99%

Preparation and characterization of hierarchical USY by post-treatment

et al. 2015

View full text Add to dashboard Cite

Two modifying agents, citric acid and EDTA2Na, were used to modify USY zeolite to obtain the hierarchical USY with high crystallinity. XRD, N 2 isothermal sorption, 27 Al and 29 Si NMR, and TEM were adopted to characterize the dealumination process in the post-treatment of USY. The results showed that all modified USY have increased surface areas and pore volume due to the removal of non-framework Al species. Besides, framework dealumination occurred in the modification process. USY-EC, which was modified by the combined effects of citric acid and EDTA-2Na, has the highest SiO 2 /Al 2 O 3 ratio of 19.40 and relatively high crystallinity.

show abstract

“…Moreover, high acid strength and density also lead to serious secondary cracking. Therefore, the modification of USY zeolites is of great significance [4].…”

Section: Introductionmentioning

confidence: 99%

“…However, H 2 SO 4 will cause a serious corrosion when it is applied in industry. Compared with inorganic acids, organic acids are more potential because they could modify the USY zeolites in moderate reaction conditions thus no obvious defects are observed in the modified products [4,25]. Previous researches [26][27][28] have shown that citric acid, acting as an organic ligand, demonstrates excellent pore-forming ability.…”

Section: Introductionmentioning

confidence: 99%

Combined modification of ultra-stable Y zeolites via citric acid and phosphoric acid

Qiao

et al. 2014

Appl Petrochem Res

View full text Add to dashboard Cite

The modification of commercial ultra-stable Y zeolites using citric acid and phosphoric acid was investigated systematically via a L 18 (3 8) orthogonal experiment. The pore structure, acid property and crystal structural of modified USY zeolites were characterized by a variety of means such as N 2 adsorption-desorption, Fourier transform infrared spectroscopy, NH 3-temperature programmed desorption and X-ray diffraction. The optimal modification condition is found to be that the volume ratio of citric acid (0.3 mol/L) and phosphoric acid (0.3 mol/L) is 1.0, and the operation is performed at 100°C for 6 h. The as-synthesized sample presents an increased secondary pore volume up to 0.207 cm 3 /g which accounts for 42.9 % of the total pore volume, and appropriate acidity distribution as well as good crystallinity. In addition, the USY obtained by 1.0 L scale-up modification possesses a secondary pore volume of 0.210 cm 3 /g which accounts for 42.4 % of the total pore volume, showing no obvious scale-up effects. Furthermore, the hydrothermal stability of the modified samples meets the requirements of commercial catalysts for hydrocracking. Performance evaluation was carried out on a 200 mL fixedbed single stage hydrogenation unit using Daqing VGO as feedstock. The 140-370°C middle distillate yield is 66.09 %, and middle distillate selectivity can reach up to 80.45 %. Compared with commercial catalyst, the yield and selectivity are increased by 5.67 and 4.07 %, respectively.

show abstract

Screening of optimum condition for combined modification of ultra-stable Y zeolites using multi-hydroxyl carboxylic acid and phosphate

Cited by 28 publications

References 32 publications

Structure Analysis in Zeolite Research: From Framework Topologies to Functional Properties

Structure Analysis in Zeolite Research: From Framework Topologies to Functional Properties

Preparation and characterization of hierarchical USY by post-treatment

Combined modification of ultra-stable Y zeolites via citric acid and phosphoric acid

Contact Info

Product

Resources

About