scholarly journals Physico-Chemical Properties of Nickel Promoted Sulfated Zirconia Powder Prepared using Different Procedures

2020 ◽  
Vol 32 (3) ◽  
pp. 555-560
Author(s):  
Amalia Kurnia Amin ◽  
Karna Wijaya ◽  
Wega Trisunaryanti
Keyword(s):  
Crystallite Size ◽  
Sulfated Zirconia ◽  
Pore Volume ◽  
Chemical Properties ◽  
Acid Sites ◽  
Impregnation Method ◽  
Zirconia Powder ◽  
Ammonia Adsorption ◽  
Physico Chemical ◽  
Zirconia Support

In this work, nickel promoted sulfated zirconia (Ni/SZ) as catalyst was prepared by either by reflux (Ni/SZ-R) or hydrothermal Ni impregnation (Ni/SZ-H) routes. The aim of this study was to evaluate the influences of two preparative methods on the physico-chemical properties of prepared catalysts. Both the catalysts were characterized by XRD, FTIR, ammonia adsorption, SEM-EDX, TEM-SAED, AAS and BET. It was found that the presence of sulfate and nickel could enhance the Brønsted and Lewis active acid sites. In relation to the effect of Ni impregnation method, acidity, amount of sulfate and Ni found in Ni/SZ-R were higher than those in Ni/SZ-H. Unfortunately, higher impregnated sulfate and nickel on zirconia support led to a decrease in surface area and pore volume and an increase in crystallite size of grainy aggregated mesoporous nickel promoted sulfated zirconia (Ni/SZ).

The Effect of the Method of Gallium Introduction into a Zeolite on its Physico-Chemical Properties and Reactivity in the Course of Propane Aromatization

2015 ◽  
Vol 670 ◽  
pp. 15-20 ◽  
Author(s):  
Ludmila N. Vosmerikova ◽  
Aleksandra N. Volynkina ◽  
Vladimir I. Zaikovskii ◽  
Aleksandr V. Vosmerikov
Keyword(s):  
Catalytic Activity ◽  
Aromatic Hydrocarbons ◽  
Pore Volume ◽  
Structural Characteristics ◽  
Chemical Properties ◽  
Acid Sites ◽  
Efficient Catalyst ◽  
Propane Aromatization ◽  
Physico Chemical ◽  
The Relationship

Different methods are used to prepare gallium-containing zeolites of a ZSM-5 structure. Their acidic and structural characteristics are investigated and the effect of the method of gallium introduction into a zeolite on distribution and ratio of acid sites of different strengths, as well as on pore volume and diameter is determined. The relationship between the localization of gallium introduced into a zeolite by different methods and its electronic state and the catalytic activity and selectivity of the resulting contacts in the course of propane aromatization is established. The Ga-containing zeolite prepared by impregnation is found to be the most efficient catalyst for conversion of propane into aromatic hydrocarbons.

Preparation of Sulfated Zirconia Using Modified Sol Gel Method

2014 ◽  
Vol 896 ◽  
pp. 153-158
Author(s):  
Anis Kristiani ◽  
Kiky C. Sembiring ◽  
Fauzan Aulia ◽  
Joddy Arya Laksmono ◽  
Silvester Tursiloadi ◽  
...  
Keyword(s):  
Sulfated Zirconia ◽  
Sol Gel ◽  
Chemical Properties ◽  
Gel Method ◽  
Sol Gel Method ◽  
Organic Bases ◽  
Physico Chemical ◽  
Medium Porosity ◽  
Cetyltrimethyl Ammonium ◽  
Physical And Chemical

A series of sulfated zirconia was prepared through sol gel method in alcohol medium. Porosity of the catalyst was developed in two different methods, which were immersion of cetyltrimethyl ammonium chloride (CTAC) surfactant as templating agent and Supercritical Fluid Extraction (SFE). The physico-chemical properties of the catalysts were characterized by Thermal Gravimetric-Differential Thermal Analysis (TG-DTA), X-ray Diffraction (XRD), Brunauer-Emmett-Teller (BET) and Barret-Joyner-Halenda (BJH) and gravimetry method for acidity measurement following by the adsorption of organic bases. The characterization results show that different method of immersing CTAC surfactant and SFE affecting physical and chemical properties, i.e. crystalinity, surface area, pore size, pore volume and acidity.

scholarly journals Influence of Polymer-Silicate Nucleator on the Structure and Properties of Polyamide 6

2020 ◽  
Vol 14 (4) ◽  
pp. 496-503
Author(s):  
Volodymyr Levytskyi ◽  
◽  
Andrii Masyuk ◽  
Diana Katruk ◽  
Rafał Kuzioła ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Crystallite Size ◽  
Softening Point ◽  
Surface Hardness ◽  
Chemical Properties ◽  
Polyamide 6 ◽  
Structure And Properties ◽  
Crystallinity Degree ◽  
Physico Chemical ◽  
Silicate Materials

Physico-chemical properties of developed nickel-containing modified silicate materials as the nucleators for composites based on polyamide 6 are presented. As it was established, additive of the nucleator modified by polyvinylpyrrolidone promotes the increase of crystallinity degree of polyamide 6 and the decrease of crystallite size. It was found that changes in the structure of the material cause the increase of its tensile strength, surface hardness and Vicat softening point.

scholarly journals Fischer-Tropsch synthesis over Co/γ-Al2O3 catalyst loaded on ceramic monolith-structured substrate

2020 ◽  
Vol 9 (3) ◽  
pp. 88-93
Author(s):  
Uy Do Pham Noa ◽  
Huan Nguyen Manh ◽  
Loc Hoang Van ◽  
Chien Luc Minh ◽  
Giang Nguyen Thi Chau ◽  
...  
Keyword(s):  
Tubular Reactor ◽  
Chemical Properties ◽  
Tropsch Synthesis ◽  
Impregnation Method ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
Physico Chemical ◽  
Bet Specific Surface Area ◽  
Slurry Method ◽  
Al2o3 Catalyst

Cobalt-based catalyst supported on γ-Al2O3­ was prepared by impregnation method and loaded on ceramic monolith-structured substrate by wash-coating slurry method. Physico-chemical properties of the catalysts were characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) specific surface area and H2 temperatured-programmed reduction (H2-TPR). Activity of the catalysts for Fischer-Tropsch synthesis was investigated in a tubular reactor in a temperature range of 200-275 oC at 20 bar and GHSV = 3000 h-1. Co/γ-Al2O3 catalyst loaded on ceramic monolith-structured substrate enhanced efficacy of Fischer-Tropsch synthesis by increasing and stabilizing CO conversion and C5+ selectivity, compared to Co/γ-Al2O3 powder catalyst.

scholarly journals PCDD/F removal at low temperatures over Vanadium-based catalyst: insight into the superiority of mechanochemical method

2021 ◽  
Author(s):  
Minghui Tang ◽  
Qiulin Ye ◽  
Cuicui Du ◽  
Yaqi Peng ◽  
Chengetai Portia Makwarimba ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Low Temperatures ◽  
Chemical Properties ◽  
Catalytic Degradation ◽  
Impregnation Method ◽  
Key Factors ◽  
Mechanochemical Method ◽  
Physico Chemical ◽  
Stable Source ◽  
Insight Into

Abstract The high toxicity and low volatility of PCDD/Fs prevent detailed study of their catalytic degradation removal characteristics. In this study, firstly, 1,2-dichlorobenzene (1,2-DCBz) was initially used as a model to investigate the catalytic characteristics of various vanadium-based catalysts prepared by different methods. Then, the optimized catalyst was used for catalytic degradation of real PCDD/Fs at low-temperatures based on a self-made stable source. The VOx/TiO2 catalysts synthesized by the mechanochemical method (VTi-MC2) had a higher 1,2-DCBz removal efficiency (> 85%) and stability (> 420 min) at low temperatures (< 200 oC) compared to VTi-SG (sol-gol method) and VTi-WI (wetness impregnation method). The physico-chemical properties of catalysts were studied using comprehensive characterization. It was found that the VTi-MC2 has better VOx species distribution and possesses the highest V5+ species and surface adsorbed oxygen content, which are the key factors contributed to the higher removal efficiency. Accordingly, the mechanochemical method can be used to control the physico-chemical properties of catalyst by adjusting the milling parameters. The optimum ball-milling time is 2 h and the suitable precursor is NH4VO3 for VOx/TiO2. Moreover, the removal efficiency of gas phase PCDD/Fs catalyzed by VTi-MC2 is 97% within a temperature range below 200 ℃, and the catalytic degradation of PCDD/Fs surges to 50%, which is higher than those reported research. In general, the mechanochemical strategy reported provides a means for seeking more efficient catalysts used for low-temperature degradation of various trace organic pollutants.

Tert-Butylation of Toluene with Tert-butanol Over Transition Metal Oxide-Modified Hbea Zeolite

2018 ◽  
Vol 42 (3) ◽  
pp. 160-165
Author(s):  
Yixian Han ◽  
Hua Song ◽  
Yuanyuan Wang ◽  
Xinglong Sun ◽  
Zhigang Sun
Keyword(s):  
Transition Metal ◽  
Metal Oxide ◽  
Chemical Properties ◽  
Transition Metal Oxide ◽  
Strong Acid ◽  
Shape Selectivity ◽  
Acid Sites ◽  
Zeolite Catalysts ◽  
Impregnation Method ◽  
Tert Butanol

A series of transition metal oxide-modified HBEA (M x0 y/HBEA) zeolite catalysts were prepared by the wetness impregnation method, and investigated for the alkylation of toluene with tert-butanol to synthesise 4- tert-butyltoluene (4-TBT). Their physico-chemical properties were characterised by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller and NH3 temperature-programmed desorption methods. M x0 y/HBEA zeolite showed higher para-selectivity than parent HBEA due to its improved structural and acidic properties. Though the toluene conversion of M x0 y/HBEA catalyst decreased, the 4-TBT selectivity increased significantly at 190 °C after 4 h. The narrowed pores after loading the M x0 y prompted an increase in selectivity for 4-TBT by increasing the shape selectivity. In addition, the decrease in strong acid sites increased selectivity for 4-TBT by suppressing further isomerisation of the 4-TBT formed on acid sites. Among all the modified HBEA zeolites, Fe203/HBEA exhibited the best catalytic activity and para-selectivity. The factors affecting the reaction over Fe203/HBEA have also been investigated extensively.

scholarly journals Characteristics and activity of Ni/CeO2 catalyst modified by Cr2O3 in combined steam and CO2 reforming of CH4

2021 ◽  
Vol 10 (1) ◽  
pp. 104-108
Author(s):  
Phuong Phan Hong ◽  
Anh Nguyen Phung ◽  
Huy Tran Anh ◽  
Tri Nguyen ◽  
Loc Luu Cam
Keyword(s):  
Chemical Properties ◽  
Catalytic Performance ◽  
Molar Ratio ◽  
Impregnation Method ◽  
Co2 Reforming ◽  
X Ray ◽  
Co2 Reforming Of Ch4 ◽  
Transmission Electron ◽  
Physico Chemical ◽  
Temperature Programmed

A series of 10%wtNiO/CeO2-nanorod catalyst without and with Cr2O3 additive was prepared by simultaneous impregnation method. Several techniques, including N2 physisorption measurements, X-ray powder diffraction (XRD), temperature-programmed reduction using H2 (H2-TPR), CO2 temperature-programmed desorption (CO2-TPD), scanning electron microscope (SEM) and transmission electron microscopy (TEM) were used to investigate catalysts’ physico-chemical properties. The activity of the catalysts in combined steam and CO2 reforming of CH4 (BRM) was investigated at temperature range of 550-800 °C. The results showed that 10%NiO0.1%Cr2O3/CeO2 catalyst had the best catalytic performance due to a better reducibility and basicity. At 700 °C and CH4:CO2:H2O molar ratio in feed stream of 3:1.2:2.4, both conversion of CH4 and CO2 on this catalyst reached 98.5%.

scholarly journals Influence of sulfating method on La–Ni–S2O82–/ZrO2–Al2O3 solid superacid catalyst for n-pentane isomerization

2020 ◽  
Vol 45 ◽  
pp. 146867831989772
Author(s):  
Haiqiang Zhao ◽  
Hua Song ◽  
Lele Zhao ◽  
Feng Li
Keyword(s):  
Infrared Spectroscopy ◽  
Pore Size ◽  
Pore Volume ◽  
Acid Sites ◽  
Impregnation Method ◽  
Bronsted Acid ◽  
Brønsted Acid Sites ◽  
X Ray ◽  
Brönsted Acid ◽  
Brönsted Acid Sites

La–Ni–S2O82–/ZrO2–Al2O3 catalysts were successfully prepared by two different methods of sulfate impregnation, and the physico-chemical properties of the catalysts were characterized by X-ray diffraction, Brunauer–Emmett–Teller analysis, Fourier transform infrared spectroscopy, pyridine adsorption–infrared spectroscopy, and X-ray photoelectron spectroscopy techniques. Catalytic activities were evaluated in a fixed-bed flow reactor using n-pentane isomerization as the probe reaction. Compared with catalyst La–Ni–S2O82–/ZrO2–Al2O3-I, prepared by the traditional impregnation method, the catalyst La–Ni–S2O82–/ZrO2–Al2O3-W, prepared by the incipient-wetness impregnation method, possessed higher pore volume, pore size, sulfur content, and stronger Brønsted acid sites. The catalytic activity for La–Ni–S2O82–/ZrO2–Al2O3-W was maintained at around 56% within 3000 min with an isopentane selectivity of 88% which showed much greater stability than that of La–Ni–S2O82–/ZrO2–Al2O3-I. This can be attributed to the fact that (1) the large pore size and pore volume of La–Ni–S2O82–/ZrO2–Al2O3-W can largely suppress carbon deposition and (2) the more numerous and stronger Brønsted acid sites for La–Ni–S2O82–/ZrO2–Al2O3-W guaranteed to provide enough acid sites for isomerization during the reaction process.

scholarly journals Influence of alumina addition on structural and catalytic properties of sulphated zirconia in isomerization of n-hexane

2021 ◽  
Vol 15 (2) ◽  
pp. 111-119
Author(s):  
Aleksandra Zarubica ◽  
Jugoslav Krstic ◽  
Dejan Popovic ◽  
Aleksandra Krstic ◽  
Radomir Ljupkovic ◽  
...  
Keyword(s):  
Calcination Temperature ◽  
Tetragonal Zirconia ◽  
Chemical Properties ◽  
Acid Sites ◽  
Catalytic Systems ◽  
Organic Precursor ◽  
Sulphated Zirconia ◽  
Calcination Temperatures ◽  
Physico Chemical ◽  
Catalytic Material

New binary catalytic systems based on sulphated zirconia-alumina were synthesized by controlled hydrolysis of alkoxides using relative molar ratios of constituents 1:1, 1:2 and 1:3 in favour of zirconia. The obtained differences in the final catalytic material?s properties may be related to organic precursor memory effect, the applied calcinations temperatures and used alumina contents. The addition of alumina to zirconia affected the structural and surface properties stabilizing bare zirconia by means of slower phase transformation of tetragonal zirconia crystal phase into monoclinic one, further resulting in smaller crystallites sizes and higher surface density of acidic function (sulphates). The best alumina impact on physico-chemical properties was achieved when the highest amount of alumina (e.g. 50%) and lower calcination temperature (500?C) were used, causing relatively high steady-state activity in isomerization of n-hexane at reaction temperature 250 ?C. On the other hand, higher calcination temperature (600 ?C) played a role in the genesis of greater sulphate density. Catalytic activity and selectivity are expressed as a complex synergistic function of relative density of acid sites together with positive status of other optimized physico-chemical properties of the catalytic material (by activation and calcination temperatures).

Decoration of specific sites on freeze-fractured membranes

1978 ◽  
Vol 36 (2) ◽  
pp. 140-141
Author(s):  
H. Gross ◽  
H. Moor
Keyword(s):  
Pure Water ◽  
Freeze Fracture ◽  
Chemical Properties ◽  
Surface Forces ◽  
Sulfate Pentahydrate ◽  
Copper Sulfate Pentahydrate ◽  
Physico Chemical ◽  
Water Of Hydration ◽  
Small Container ◽  
Binding Forces

Fracturing under ultrahigh vacuum (UHV, p ≤ 10-9 Torr) produces membrane fracture faces devoid of contamination. Such clean surfaces are a prerequisite foe studies of interactions between condensing molecules is possible and surface forces are unequally distributed, the condensate will accumulate at places with high binding forces; crystallites will arise which may be useful a probes for surface sites with specific physico-chemical properties. Specific “decoration” with crystallites can be achieved nby exposing membrane fracture faces to water vopour. A device was developed which enables the production of pure water vapour and the controlled variation of its partial pressure in an UHV freeze-fracture apparatus (Fig.1a). Under vaccum (≤ 10-3 Torr), small container filled with copper-sulfate-pentahydrate is heated with a heating coil, with the temperature controlled by means of a thermocouple. The water of hydration thereby released enters a storage vessel.

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