Abstract In the present study, a facile and one step approach has been developed for the synthesis of hierarchical porous zeolite-Y using bifunctional cationic polymer, polydiallyldimethyl ammonium chloride (PDDA) as a mesopore directing template. The effects of various synthesis parameters such as hydrothermal reaction temperature, time, amount of PDDA and NaOH were systematically investigated to produce crystalline and hierarchical zeolite-Y crystals (PDYs). All the synthesized zeolite-Y samples were characterized by XRD, FT-IR, SEM, EDAX, TEM, TGA, CO2-TPD and Nitrogen adsorption-desorption measurements. The characterization results showed that the zeolite-Y samples synthesized at optimized ratios of PDDA/Al2O3 and NaOH/Al2O3 exhibited higher crystallinity, higher BET surface area and larger total pore volume in comparison to the sample synthesized in the absence of the template (ZY). Interestingly, the hierarchical porous zeolite-Y samples (PDY-7) displayed substantial enhancement in CO2 adsorption capacity (5.40 mmol/g) at 298 K and 100 kPa as compared to the non-templated one (ZY) (4.5 mmol/g). The effective improvement in CO2 adsorption performance of PDY samples is attributed to the existence of interconnected micro-meso channel network, the higher total pore volume and higher concentration of acid-base sites (due to the lower Si/Al ratio). Owing to the higher CO2 adsorption capacity, the PDY samples also displayed high equilibrium selectivity for CO2 over N2 (∼250) as well as over CH4 (∼110) at 298 K. The enhanced CO2 adsorption capacity combined with the high CO2 adsorption selectivity renders the hierarchical zeolite-Y an excellent contender for the efficient CO2 capture.
Abstract Zeolite-Y is one of the preferred micro-sized zeolite commonly used as a catalyst and for adsorption and separation. The size and shape of zeolite crystals have great influence on their properties therefore the synthesis of nano-size zeolite-Y has received much attention with straightforward methodology. In the present study, nano-sized zeolite-Y crystals were synthesized by the clear-solution (CS) and dense-gel (DG) methods in the presence of alkali metal chloride salt (i.e. NaCl) unde...
Abstract The aim of this study is to exploit low-cost N-doped porous carbonaceous adsorbents with excellent CO 2 adsorption properties. Herein, the N-enriched porous carbons were obtained through a single-step sodium amide activation of carbonized water chestnut shell at 400-500°C. The optimal sample possesses high CO 2 uptake of 4.50 mmol/g (25°C) and 6.04 mmol/g (0°C) at atmospheric pressure. Additionally, this sample displays high CO 2 /N 2 selectivity, stable cyclic ability, moderate CO 2 is...
Last. Sung Hwa Jhung(KNU: Kyungpook National University)H-Index: 78
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Abstract Highly porous metal-organic framework (MOF), MIL-101(Cr), was modified by introduction of polyaniline (PANI) via ship in bottle strategy in order to utilize basic moieties of PANI in capturing CO2 effectively from flue gas. PANI@MIL-101(Cr), with suitable PANI concentration, showed highly increased adsorption capacity for CO2, especially at low pressure of 0.15 atm, even though the porosity of MIL-101(Cr) was decreased upon PANI loading. Moreover, the PANI@MIL-101(Cr) showed increased s...
Abstract Herein, we report the synthesis of hierarchical AlPO4-5 and SAPO-5 molecular sieves that exhibit varying degrees of mesoporous interconnectivity by controlling the amount of triethylamine (TEA) (used as the structure directing agent) and the Si-to-Al ratio (Si/Al); the gel mixture had a composition of (1 − y) Al2O3:y SiO2:1.3 P2O5:x TEA:200 H2O. The molecular sieves were characterized by X-Ray powder Diffraction (XRD) and Scanning Electron Microscopy/Energy Dispersive X-Ray Spectroscopy...
Abstract Zeolite-Y with different particle size was synthesized and the growth of crystals was studied in the presence of a cationic polyelectrolyte (PDDA) functionalized graphene oxide (PDDA-GO). The assembly of PDDA-GO was found to be cooperative in the growth of pure zeolite-Y crystals with various particle sizes (400 nm and 100 nm). The submicron size zeolite-Y particles were grown with entrapment of the GO nanosheets and the complete removal of PDDA-GO by calcination under air atmosphere as...
Hierarchical porous ZSM-5 (HP-ZSM-5) was constructed using organosilanes as the growth inhibitors for CO2 capture. The properties of adsorbents were characterized by X-ray diffraction, N2 adsorption/desorption, scanning electron microscopy, temperature-programmed desorption of carbon dioxide, and 27Al magic angle spinning nuclear magnetic resonance. It was found that HP-ZSM-5 samples synthesized by organosilanes had a significant effect on the microstructure and morphology. CO2 adsorption capaci...
Abstract Bifunctional palladium-based catalysts with zeolite supports were investigated in phenol hydroalkylation, representing high-potential model reaction for transformation of lignocellulose-derived compounds to automotive and jet fuels. Conversion of phenol correlated with the amount of accessible acid sites and textural properties of the solid acid support: under the same reaction conditions and at the same Pd loading. The highest phenol conversions (99–100%) were obtained for large-pore z...
Last. Hani M. El-Kaderi(VCU: Virginia Commonwealth University)H-Index: 33
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Development of efficient sorbents for carbon dioxide (CO2) capture from flue gas or its removal from natural gas and landfill gas is very important for environmental protection. A new series of heteroatom-doped porous carbon was synthesized directly from pyrazole/KOH by thermolysis. The resulting pyrazole-derived carbons (PYDCs) are highly doped with nitrogen (14.9–15.5 wt %) as a result of the high nitrogen-to-carbon ratio in pyrazole (43 wt %) and also have a high oxygen content (16.4–18.4 wt ...
#1Kai Zhang(SCUT: South China University of Technology)H-Index: 36
#1Kai Zhang(SCUT: South China University of Technology)H-Index: 31
Last. Hongxia Xi(SCUT: South China University of Technology)H-Index: 30
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Hierarchical zeolites are important solid catalysts for the conversion of bulky molecules according to their mesoporosities. In this study, we prepared a hierarchically structured beta zeolite by using a bifunctionalized amphiphilic surfactant, C18-6-diphe, under hydrothermal synthesis conditions. The product was characterized by a combination of X-ray powder diffraction, N2 adsorption–desorption isotherms, scanning electron microscopy, transmission electron microscopy, Fourier transform infrare...
Last. Dengwei Jing(Xi'an Jiaotong University)H-Index: 36
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Abstract null null With the advantages of high efficiency, clean and renewable energy, the technology of sorption/desorption-based atmospheric water harvesting powered by solar energy has gradually attracted the increasing attention of researchers. In this review paper, through analyzing and summarizing the principles, the performance indexes, the measurements of parameters, the material types, the morphology modification, and the system design and devices of this technology, it was found that t...
Abstract null null The development of efficient zeolite-based adsorbents with high water uptake capacity is an essential requirement for water adsorption and moisture removal technologies. In the present study, zeolite-Y samples with interconnected hierarchical micro-mesoporous network were synthesized by employing a bifunctional cationic polymer (namely, polydiallydimethyl-ammonium chloride, PDDA), and ion-exchanged with several metal salts (such as Zn, Mg, Li) targeting high capacity water ads...
Abstract In this work, the waste biomass lotus leaf was converted into N-doped porous carbonaceous CO2 adsorbents. The synthesis process includes carbonization of lotus leaf, melamine post-treatment and KOH activation. For the resultant sorbents, high nitrogen content can be contained due to the melamine modification and advanced porous structure were formed by KOH etching. These samples were carefully characterized by different techniques and their CO2 adsorption properties were investigated in...
The constant increase of CO2 concentration in the atmosphere is recognized worldwide to severely impact the environment and human health. Zeolites possess a high adsorption capacity for CO2 removal, but their powdery form prevents their use in many practical applications. When binding agents are used, a partial occlusion of the porosity can severely compromise the adsorption capacity. In this regard, a great challenge is producing compact composite adsorbents while maintaining a high specific su...
Last. Yang Liu(Northeast Petroleum University)H-Index: 9
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We adopted grand canonical Monte Carlo (GCMC) simulations to comprehensively investigate the adsorption of CO2/N2 mixtures of different compositions in well-shaped single-walled carbon nanotubes (C...
#1Ru‐Shuai Liu(DUT: Dalian University of Technology)
#1An-Hui Lu(DUT: Dalian University of Technology)H-Index: 62
Last. Shaoyun Chen(DUT: Dalian University of Technology)
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The atmospheric CO 2 concentration continues a rapid rise to its current record high value of 416 ppm for the time being. It calls for advanced CO 2 capture technologies. One of the attractive technologies is physical adsorption-based separation, which shows easy regeneration and long cycle stability, and thus reduced energy penalties and cost. The extensive research on this topic is evidenced by the growing body of scientific and technical literature. The progress spans from the innovation of n...
Abstract The formation of urea linkages is a limitation to the application of solid amine CO2 adsorbents. Therefore, the development of solid amine adsorbents with resistance to urea linkage formation has attracted much interest over the last 5 years. In this study, we developed a facile method for synthesizing solid amine adsorbents with effective resistance to urea linkage formation. For the first time, metal nitrates were used to modify amorphous nano SiO2 to support polyethyleneimine (PEI). ...
#1Yu Li(Guilin University of Technology)H-Index: 1
#2Jianwen Wei(Guilin University of Technology)H-Index: 4
Last. Lei Liao(Guilin University of Technology)H-Index: 5
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An amine-modified Beta/KIT-6 (BK) micro/mesoporous composite for CO2 capture was synthesized using nonionic tri-block copolymer pluronic (P123) as a template, tetraethyl orthosilicate (TEOS) as a s...