Microporous Rhodium(II) 4,4′,4″,4″′-(21H,23H-porphine-5,10,15,20-tetrayl)tetrakisbenzoate. Synthesis, Nitrogen Adsorption Properties, and Catalytic Performance for Hydrogenation of Olefin

2003 ◽  
Vol 32 (9) ◽  
pp. 854-855 ◽  
Author(s):  
Tomohiko Sato ◽  
Wasuke Mori ◽  
Chika Nozaki Kato ◽  
Tetsushi Ohmura ◽  
Tsubasa Sato ◽  
...  
Keyword(s):  
Nitrogen Adsorption ◽  
Catalytic Performance ◽  
Adsorption Properties

scholarly journals ADSORPTION PROPERTIES OF TITANIA-SILICA MEMBRANES OBTAINED ON CERAMIC SUBSTRАTE

2018 ◽  
Vol 54 (3) ◽  
pp. 274-280
Author(s):  
T. F. Kouznetsova ◽  
A. I. Ivanets ◽  
J. D. Sauka
Keyword(s):  
Surface Area ◽  
Quartz Substrate ◽  
Cetylpyridinium Chloride ◽  
Nitrogen Adsorption ◽  
Mesoporous Structure ◽  
Adsorption Properties ◽  
Molar Ratio ◽  
Silica Membranes ◽  
Metal Silicate ◽  
Adsorption Desorption

Titania-silica membranes on a porous quartz substrate are prepared by its direct contact with metal silicate sol at various Ti/Si ratios in the conditions of coagel sedimentation and presence of cetylpyridinium chloride. The study of textural and adsorption properties of membranes is conducted by low-temperature nitrogen adsorption-desorption, including methods of t-plots and DFT theory. It was shown that obtained membranes have mesoporous structure with the specific surface area and pore hydraulic diameter varied in intervals of 64–217 m2 /g and 4–11 nm, respectively. Developed values of surface area remain up to molar ratio of Ti/Si = 50/50.

One-Step Synthesis of Rod-Shaped NiFe-MOF as a Highly Efficient Oxygen Evolution Catalyst

NANO ◽  
2019 ◽  
Vol 14 (08) ◽  
pp. 1950101 ◽  
Author(s):  
Dandan Zhang ◽  
Renxing Huang ◽  
Huaming Xie ◽  
Xingyong Liu ◽  
Ying Lei ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Low Cost ◽  
Metal Organic Framework ◽  
Electrochemical Techniques ◽  
Nitrogen Adsorption ◽  
Catalytic Performance ◽  
Highly Efficient ◽  
Transmission Electron

Development of low-cost, highly active catalyst for efficient oxygen evolution reaction based on earth-abundant metals is still a great challenge. Here, we report that a rod-like bimetallic NiFe metal-organic framework (NiFe-MOF) can directly act as a highly efficient oxygen evolution reaction (OER) catalyst synthesized by a convenient-to-operate hydrothermal method. The rod-like NiFe-MOF can derive 10[Formula: see text]mA[Formula: see text]cm[Formula: see text] with a low overpotential of only 26[Formula: see text]mV, and its Tafel slope is 40.82[Formula: see text]mV[Formula: see text]dec[Formula: see text], which is superior to that of monometallic Ni-MOF or Fe-MOF, and even can be comparable to that of RuO2. To identify the origin of enhancing OER activity, we resorted to X-ray diffraction, scanning electron microscope, transmission electron microscope, high resolution transmission electron microscopy image and nitrogen adsorption–desorption techniques and various electrochemical techniques to probe it gingerly. The results indicate that its high electrochemically active area and the synergistic effect of bimetallic node could be responsible for the surprisingly high catalytic performance of the NiFe-MOF. These results suggest that this kind of bimetallic MOF (NiFe-MOF) could be a promising electrocatalyst for oxygen evolution reaction.

scholarly journals Interconnected Micro, Meso, and Macro Porous Activated Carbon from Bacterial Nanocellulose for Superior Adsorption Properties and Effective Catalytic Performance

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4063
Author(s):  
Arnon Khamkeaw ◽  
Tatdanai Asavamongkolkul ◽  
Tianpichet Perngyai ◽  
Bunjerd Jongsomjit ◽  
Muenduen Phisalaphong
Keyword(s):  
Activated Carbon ◽  
Reaction Temperature ◽  
Mass Transfer Rate ◽  
Catalyst Support ◽  
Catalytic Performance ◽  
Adsorption Properties ◽  
Bet Surface Area ◽  
Ethanol Conversion ◽  
Bacterial Nanocellulose ◽  
Effective Performance

The porous carbon (bacterial cellulose (BC)-activated carbon (AC)(BA)) prepared via two-step activation of bacterial nanocellulose by treatments with potassium hydroxide (KOH) and then phosphoric acid (H3PO4) solutions showed superior adsorption properties and effective performance as catalyst support. BC-AC(BA) had an open and interconnected multi-porous structure, consisting of micropores (0.23 cm3/g), mesopores (0.26 cm3/g), and macropores (4.40 cm3/g). The BET surface area and porosity were 833 m2/g and 91.2%, respectively. The methylene blue adsorption test demonstrated that BC-AC(BA) was superior in its mass transfer rate and adsorption capacities. Moreover, BC-AC(BA) modified by H3PO4 treatment showed a significant enhancement of catalytic performance for dehydration of ethanol. At the reaction temperature of 250–400 °C, 30P/BC-AC(BA) gave ethanol conversion at 88.4–100%, with ethylene selectivity of 82.6–100%, whereas, high selectivity for diethyl ether (DEE) at 75.2%, at ethanol conversion of 60.1%, was obtained at the reaction temperature of 200 °C.

Silica-supported Cu–Pt bimetallic catalysts for liquid-phase diethyl oxalate hydrogenation

2018 ◽  
Vol 96 (4) ◽  
pp. 394-403 ◽  
Author(s):  
Wei Long ◽  
Pingle Liu ◽  
Yang Lv ◽  
Wei Xiong ◽  
Fang Hao ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Photoelectron Spectroscopy ◽  
Bimetallic Catalysts ◽  
Nitrogen Adsorption ◽  
Hydrogen Uptake ◽  
Copper Catalysts ◽  
Catalytic Performance ◽  
Diethyl Oxalate ◽  
Hydrogen Chemisorption ◽  
Adsorption Desorption

Silica-supported copper catalysts were prepared by different methods, and Cu/SiO2 prepared by the urea-assisted gel method was modified with co-catalyst platinum to obtain Cu-Pt/SiO2 bimetallic catalysts. The prepared catalysts were characterized by nitrogen adsorption–desorption, XRD, TEM, hydrogen chemisorption, ammonia gas chemisorption, and X-ray photoelectron spectroscopy. The characterization results show that the modification of platinum is helpful to the reduction and dispersion of copper species, which increase the hydrogen uptake quantity and metal surface area. The 30%Cu–3.0%Pt/SiO2-6 presents the best catalytic performance in liquid-phase diethyl oxalate hydrogenation; it gives 77.32% conversion of diethyl oxalate and 94.37% selectivity to the main products under 473 K and 3.0 MPa for 4 h. A possible reaction route was also proposed.

Methanol Conversion to Propylene over Mo-HZSM-5 Zeolite

2013 ◽  
Vol 834-836 ◽  
pp. 476-480
Author(s):  
Hai Rong Zhang ◽  
Hong Yan Liu ◽  
Yu Jiang ◽  
Xiao Hua Chang ◽  
Kai Yuan ◽  
...  
Keyword(s):  
Hydrothermal Method ◽  
Surface Area ◽  
Fixed Bed ◽  
Nitrogen Adsorption ◽  
Methanol Conversion ◽  
Catalytic Performance ◽  
Bet Surface Area ◽  
Al Content ◽  
Strong Acidity

A series of Mo-ZSM-5 zeolites have been synthesized by in site hydrothermal method and their catalytic performance for methanol conversion to propylene was tested in a fixed bed reaction at WHSV=4 h-1, pressure of 1 atm, and MeOH/H2O (mol) ratio of 1. The effect of Mo and Al content on the structure and acidity of Mo-ZSM-5 zeolites were characterized by nitrogen adsorption and NH3-TPD. The results showed that Mo incorporation gradually decreased the BET surface area and weaken the strong acidity on the surface of the zeolites. At 470 °C, the maximum selectivity of propylene and the P/E (Propylene to Ethane) ratio were achieved 45.04 % and 7.30, which were higher than those over Mo free HZSM-5 by 4.12% and 3.47, respectively. Mo-ZSM-5 zeolites are promising catalysts for methanol conversion to propylene with a high P/E.

Adsorption Properties of Self-Assembly Synthesized Microporous Silica Material from Acidic Aqueous Media

2011 ◽  
Vol 179-180 ◽  
pp. 519-522
Author(s):  
Yan Yan Ji ◽  
Biao Zhang ◽  
Xiao Chun Wang
Keyword(s):  
Self Assembly ◽  
Aqueous Media ◽  
Nitrogen Adsorption ◽  
Adsorption Properties ◽  
Relative Pressure ◽  
Microporous Silica ◽  
Acidic Aqueous Solution ◽  
Silica Material ◽  
Adsorption Analysis ◽  
Volatile Organic

Microporous silica material AMPS has been synthesized via TEA+ cations assisted self-assembly of silica species in acidic aqueous solution. Nitrogen adsorption analysis revealed 0.65 nm uniform micropores in AMPS, companied with a Langmuir surface area of 745 m2/g and a pore volume of 0.22 cm3/g. The microporous AMPS exhibited an excellent adsorptive performance for volatile organic compounds (VOC) such as cyclohexane and acetone, compared with conventional zeolites such as Y, ZSM-5 and A. The adsorption was rapidly saturated at lower relative pressure with higher capacities than that of conventional zeolites. These features implied promising potentials in the separation and removal of VOCs in the atmosphere by using APS-3.

Oxidative Dehydrogenation of Ethane on Vanadium-Containing Aluminophosphates with AFI Structure

1998 ◽  
Vol 63 (11) ◽  
pp. 1869-1883 ◽  
Author(s):  
Teresa Blasco ◽  
Patricia Concepción ◽  
José M. López Nieto ◽  
Arturo Martínez-Arias
Keyword(s):  
Hydrothermal Synthesis ◽  
Molecular Oxygen ◽  
Oxidative Dehydrogenation ◽  
Diffuse Reflectance ◽  
Catalytic Properties ◽  
Nitrogen Adsorption ◽  
Catalytic Performance ◽  
Oxidative Dehydrogenation Of Ethane ◽  
Catalytic Behaviour ◽  
Acid Character

MeAPO-5 (Me = V, Mg, Co, Mn) and VMeAPO-5 (Me = Mg, Co, Mn) with AFI structure were prepared by hydrothermal synthesis and characterized by nitrogen-adsorption, TPR, diffuse reflectance (UV-VIS) and ESR spectroscopies. Their catalytic performance in the oxidative dehydrogenation of ethane using molecular oxygen was also studied. Although different catalytic behaviour was observed depending on the metal incorporated, Vanadia-metal containing materials were the most selective catalysts. The importance of both redox and acid character of the catalysts on their catalytic properties is discussed.

scholarly journals Preparation of GO/MIL-101(Fe,Cu) composite and its adsorption mechanisms for phosphate in aqueous solution

2021 ◽  
Author(s):  
You Wu ◽  
Zuannian Liu ◽  
Bakhtari Mohammad Fahim ◽  
Junnan Luo
Keyword(s):  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Adsorption Mechanism ◽  
Nitrogen Adsorption ◽  
Adsorption Properties ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorption Mechanisms ◽  
Adsorption Desorption

Abstract In this study, MIL-101(Fe), MIL-101(Fe,Cu), and Graphene Oxide (GO) /MIL-101(Fe,Cu) were synthesized to compose a novel sorbent. The adsorption properties of these three MOFs-based composites were compared toward the removal of phosphate. Furthermore, the influencing factors including reaction time, pH, temperature and initial concentration on the adsorption capacity of phosphate on these materials as well as the reusability of the material were discussed. The structure of fabricated materials and the removal mechanism of phosphate on the composite material were analyzed by Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), nitrogen adsorption-desorption analysis and zeta potential. The results show that the maximum adsorption capacity of phosphate by the composite GO/MIL-101(Fe,Cu)-2% was 204.60 mg·g− 1, which is higher than that of MIL-101(Fe,Cu) and MIL-101(Fe). likewise the specific surface area of GO/MIL-101(Fe,Cu)-2% is 778.11 m2/g is higher than that of MIL-101(Fe,Cu) and MIL-101(Fe),which are 747.75 and 510.66m2/g respectively. The adsorption mechanism of phosphate is electrostatic attraction, form coordination bonds and hydrogen bonds. The fabricated material is a promising adsorbent for the removal of phosphate with good reusability.

scholarly journals Study of sepiolite from Goles (Kosovo, Yugoslavia). II. Acid activation

2002 ◽  
Vol 67 (7) ◽  
pp. 499-506 ◽  
Author(s):  
Marina Radojevic ◽  
Vidojko Jovic ◽  
Dragomir Karaulic ◽  
Dragomir Vitorovic
Keyword(s):  
Specific Surface ◽  
Chemical Treatment ◽  
Acid Treatment ◽  
Nitrogen Adsorption ◽  
Adsorption Properties ◽  
Acid Activation ◽  
Surface Areas ◽  
Bet Method ◽  
Specific Surface Areas ◽  
Enhanced Adsorption

The changes in the pore structure and adsorption properties of sepiolite from Goles resulting from treatment with 4MHCl for various periods of time were investigated. The BET method specific surface areas, pore volumes and f ? plots were determined by nitrogen adsorption. The surface area progressively increased during the 70 hours of acid treatment, when a maximum was attained. The differences in the adsorption properties of the original and the acid treated sepiolite were evaluated by comparison of adsorption isotherms obtained with benzene, n-hexane, methanol and isooctane. The enhanced adsorption of isooctane was of great interest, since the sorption of this compound on natural sepiolites is generally very limited. The results suggest that chemical treatment of sepiolite with 4MHCl for 70 h produces an adsorbent of optimal porosity and other adsorption properties.

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