Synthesis of NaP zeolite at room temperature and short crystallization time by sonochemical method

Pal, Pameli; Das, Jugal Kishore; Das, Nandini; Bandyopadhyay, Sibdas

doi:10.1016/j.ultsonch.2012.07.012

Cited by 113 publications

(74 citation statements)

References 23 publications

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“…The first peak at 163ºC in the profiles of both samples can be attributed to desorption of water molecules present on external and internal surfaces, that accompanied by weight losses of 8.0 and 15.0 wt.% for samples made with the Na 2 O/SiO 2 ratio of 1.10 and 1.13, respectively. The second peak appeared at around 328ºC with weight losses of 4.45% and 2.88% for the former and latter, respectively, corresponding to decomposition and removal of hydroxyl groups in the synthesized zeolites [28]. This means that the removal of hydroxyl groups in the synthesized NaP zeolite increases with decreasing the Na 2 O/SiO 2 molar ratio.…”

Section: Science China Materialsmentioning

confidence: 90%

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Controllable synthesis of NaP zeolite and its application in calcium adsorption

et al. 2015

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functional performance of the different kinds of zeolites, many studies have been devoted to improving synthetic approaches to control crystal size, the size of the intracrystalline pore/channel system and morphology of zeolites [5,6].Among various types of zeolites, NaP (Na 6 [(AlO 2 ) 6 (SiO 2 ) 10 ]⋅15H 2 O) is one of the most interesting structured zeolite with two sets of intersecting channels: 0.31 nm × 0.44 nm and 0.26 nm × 0.49 nm. According to International Zeolite Association (IZA), this structure is called "Gismondine" (GIS) framework topology [7,8]. NaP zeolite offers the greatest promise for gas separation applications due to its small pore size [9,10], and is also useful for removal of toxic and radioactive waste species like Cs, Sr, Ba, Pb, U, heavy metals, and ammonium from wastewater, seawater potassium extraction and formation of environmental friendly detergent [11,12]. NaP zeolite can be synthesized from various precursor materials and various methods. It can be synthesized from: (i) clay at a crystallization temperature of 85ºC [13], (ii) sodium silicate solution [14], and (iii) high silicon fly ash of coal combustion at 120ºC for 4 h [15]. Among them the most common methods used for the synthesis of NaP zeolite are the sol-gel technique, hydrothermal synthesis and microwave heating synthesis [1]. The NaP zeolite with different morphologies can offer many intriguing properties: places to store the guest molecules and to perform chemical reactions with selected-sized molecules. Thus, the NaP zeolite morphology and its important correlation with properties is the need of the recent research.In this work, we attempted the template free hydrothermal synthesis of NaP under controlled conditions. Based on multiple paths that can be involved in the hydrothermal synthesis of NaP, optimization of crystallization conditions was adapted through variation of the following parameters: Na 2 O/SiO 2 and SiO 2 /Al 2 O 3 molar ratios, aging time and aging temperature. The characteristics of the synthesized gels NaP zeolite particles were prepared through a template-free hydrothermal condition at 100ºC. Parameters like Na2O/SiO2 and SiO2/Al2O3 molar ratios, gel aging time and aging temperature were investigated for regulating the crystallization of the final product. The samples at different synthesis stages were characterized with N2 adsorption at −196ºC, field emission scanning electron microscopy (FE-SEM), temperature programmed desorption of ammonia adsorption, X-ray diffraction, thermogravimetric and differential scanning calorimetry analysis and Fourier transform infrared spectroscopy. The experimental results evidenced that a high ordering crystallinity of NaP zeolite was obtained at Na2O/SiO2 and SiO2/Al2O3 molar ratios of 1.10 and 1.40, respectively, and a temperature of 100°C for 4 days of aging. FE-SEM image exhibited polycrystalline aggregates of NaP zeolite with crystallite sizes ranging up to 5.04 μm with cactus/cabbage like structures. The quantitative analysis of the total number of acid sites...

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Section: Science China Materialsmentioning

confidence: 90%

“…The IR band at 3519 cm −1 was assigned to hydrogen bonded Si-OH groups, while the band at 1647 cm −1 was ascribed to the bending vibration mode of residual H 2 O molecules in the zeolite voids [27,28].…”

Section: Science China Materialsmentioning

confidence: 99%

Controllable synthesis of NaP zeolite and its application in calcium adsorption

et al. 2015

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“…The catalysts mixtures were then calcined in air at 500 °C for 4 hours, yielding a homogeneous catalyst powder, according to Klimova et al [24] and Maciel et al [25]. Calcining the synthesized catalysts powders also removes structure directing agents and other organic substances present in them [26]. …”

Section: Preparation Of Zeolite Nay Supportermentioning

confidence: 99%

The Effects of Different Ratios of Sonochemically Assisted Nickel Oxide and Zirconium Oxide Catalysts in Syngas Production

2017

MJAS

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Heterogeneous catalytic cracking is currently one of the most effective ways for both reducing tar content and enhancing hydrogen (H 2 ) content in syngas at relatively low temperature, besides being environmental friendly. Sonochemical treatment has also been shown to lower reaction times with enhanced reaction rate and enables production of particles with high surface area. Two different types of metal oxides, which are Nickel Oxide (NiO) and Zirconium Oxide (ZrO 2 ) at combinations of 1:1, 1:2 and 2:1 ratios with Zeolite NaY as the supporter were synthesized via sonochemical treatment. The catalysts were then characterized using X-Ray Diffraction (XRD), Temperature Programmed Reduction in H 2 /Argon (TPR-H 2 ), Brunauer-EmmettTeller surface measurement (BET), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). From SEM and TEM analysis, nickel tends to agglomerate and form globular shapes, zirconium forms coral-like branching structure and Zeolite NaY forms stacks of cubic clumps. The most promising NiO to ZrO 2 ratio for syngas production is 1:1 because it removes the most reactive oxygen during hydrogen reduction at 0.83 x10 21 atoms/g, has small crystallite size at 56.90 nm and has the highest surface area for maximum contact with the reactants at 506.52 m 2 /g. Generally, sonochemical treatment also reduces the catalysts crystallite size (54.83 nm) and increases the catalysts surface area (506.52 m 2 /g) and oxygen removal (0.83 x10 21 atoms/g) as well as lowers the reduction temperature (637 K) which is favourable in term of production cost.Keywords: heterogeneous catalysts, nickel oxide, zirconium oxide, zeolite, syngas Abstrak Perekahan pemangkin heterogen adalah salah satu cara terkini yang paling efektif untuk mengurangkan kandungan tar dan juga meningkatkan kandungan hidrogen (H 2 ) di dalam singas pada suhu rendah, di samping mesra alam sekitar. Rawatan sonokimia juga telah dibuktikan dapat mengurangkan masa tindak balas di samping meningkatkan kadar tindak balas dan membolehkan penghasilan partikel dengan luas permukaan yang tinggi. Dua jenis besi oksida berbeza, iaitu Nikel Oksida (NiO) dan Zirkonium Oksida (ZrO 2 ) dalam kombinasi nisbah 1:1, 1:2 dan 2:1 dan Zeolit NaY sebagai penyokong dihasilkan melalui rawatan sonokimia. Katalis -katalis tersebut kemudian dianalis menggunakan pembelauan sinar-X (XRD), Penurunan Suhu Berprogram (TPR-H 2 ), pengukuran permukaan Brunauer-Emmett-Teller (BET), Mikroskop Imbasan Elekron (SEM) dan Mikroskop Elektron Transmisi (TEM). Daripada analisis SEM dan TEM, nikel cenderung untuk bergumpal dan membentuk glob besar, zirkonium membentuk struktur seperti karang bercabang dan Zeolit NaY membentuk lapisan kubik. Nisbah NiO kepada ZrO 2 yang paling atom/g, mempunyai saiz kristal yang kecil iaitu 56.90 nm dan mempunyai luas permukaan yang paling tinggi pada 506.52 m 2 /g untuk kontak maksimum dengan bahan tindak balas. Umumnya rawatan sonokimia juga mengurangkan saiz kristal katalis (54.83 nm) dan meningkatkan luas permukaan pemangki...

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“…The optimum conditions for maximum zeolite crystallinity (97%) were obtained in 55 min using microwaveassisted ageing and 4 h for the hydrothermal crystallization time. Recently, Pal et al [48] synthesized zeolite Na-P from pure chemicals by sonochemical method and compared the results with conventional hydrothermal technique. The precursors were mixed at room temperature for 1 h and then sonicated for 3 h. During the sonication, the temperature of bulk reaction mixture raised up to 80°C.…”

Section: Introductionmentioning

confidence: 99%