Effect of manganese on the thermostability and reducibility of cobalt nanomaterials.

2012 ◽  
Vol 1373 ◽  
Author(s):  
Zofia Lendzion-Bieluń
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Cobalt Oxide ◽  
High Temperatures ◽  
Specific Surface Area ◽  
Small Addition ◽  
Impregnation Method

ABSTRACTCobalt nanomaterials with promoters have been prepared by precipitation followed by calcination and impregnation method. The obtained materials are characterized by ICP, H2-TPR, BET and XRD. A small addition of manganese increases the specific surface area of cobalt nanomaterials and thermostability under reduction atmosphere. Bulk Co3O4 has been reduced in two steps (Co3+→Co2+→Co). A small addition of manganese to the cobalt oxide shifts the reduction peaks to high temperatures.

Preparation and Characterization of the Typical Pt-NSR Catalyst

2011 ◽  
Vol 412 ◽  
pp. 365-369
Author(s):  
Yuan Feng Huang ◽  
Wei Jun Zhang ◽  
Li Shen ◽  
Jin Hu ◽  
Zhuo Heng Li ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Performance Testing ◽  
High Specific Surface Area ◽  
Impregnation Method ◽  
Temperature Programmed Reduction ◽  
Temperature Programmed ◽  
Co Precipitation

A series of Ba-Al-O NSR supports and Pt/Ba-Al-O NSR catalysts are prepared by co-precipitation and impregnation method in this work. The catalyst and the support are characterized by XRD, SEM, SBET performance testing. The structure and texture of the supports is observed and discussed. The results of SBET indicate that the supports possess relative high specific surface area (94~110 m2/g). Temperature programmed reduction is characterized by means of H2-TPR.

Preparation, Characterization and Visible-Light Photocatalytic Properties of BiOCl/BiOI Nanocomposites

2012 ◽  
Vol 586 ◽  
pp. 10-17 ◽  
Author(s):  
Kai Jin Huang ◽  
Hou Guang Liu ◽  
Fang Li Yuan ◽  
Chang Sheng Xie
Keyword(s):  
Visible Light ◽  
Specific Surface ◽  
Surface Area ◽  
Quantum Efficiency ◽  
Specific Surface Area ◽  
Light Absorption ◽  
Critical Factor ◽  
Photocatalytic Properties ◽  
Impregnation Method ◽  
Visible Light Photocatalytic

BiOCl/BiOI nanocomposites were synthesized using a thermal impregnation method for the first time. The intense visible-light absorption and large specific surface area gave 4wt.％BiOCl/BiOI nanocomposites the best visible-light photocatalytic properties among all the catalysts for the photodegradation of methyl orange,about 78％ after 2 h. But decreased activities were obtained with the increase of BiOCl content in the nanocomposites. Considering the light absorption,specific surface area and the quantum efficiency, the high recombination of the photoinduced electron-hole pairs of the catalysts that lowed the quantum efficiency was believed to be the critical factor for their decreased photocatalytic activities.

scholarly journals The effect of aluminium oxide on the reduction of cobalt oxide and thermostabillity of cobalt and cobalt oxide

2011 ◽  
Vol 9 (5) ◽  
pp. 834-839 ◽  
Author(s):  
Zofia Lendzion-Bieluń ◽  
Roman Jędrzejewski ◽  
Walerian Arabczyk
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Cobalt Oxide ◽  
Specific Surface Area ◽  
Hydrogen Reduction ◽  
Aluminium Oxide ◽  
Reduction Process ◽  
Oxide Phase ◽  
Recrystallization Process ◽  
Average Size

AbstractDuring precipitation and calcination at 200°C nanocrystalline Co3O4 was obtained with average size crystallites of 13 nm and a well developed specific surface area of 44 m2 g−1. A small addition of a structural promoter, e.g. Al2O3, increases the specific surface area of the cobalt oxide (54 m2 g−1) and decreases the average size of crystallites (7 nm). Al2O3 inhibits the reduction process of Co3O4 by hydrogen. Reduction of cobalt oxide with aluminium oxide addition runs by equilibrium state at all the respective temperatures. The apparent activation energy of the recrystallization process of the nanocrystalline cobalt promoted by the aluminium oxide is 85 kJ mol−1. Aluminium oxide improves the thermostability of both cobalt oxide and the cobalt obtained as a result of oxide phase reduction.

Sintesis katalis NiMo untuk hydrotreating coker nafta

2018 ◽  
Vol 5 (1) ◽  
pp. 365
Author(s):  
Hidayah Dwi Lestari ◽  
S Subagjo ◽  
IGBN Makertihartha
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Catalyst Activity ◽  
Catalyst Characterization ◽  
Impregnation Method ◽  
Solution Ph ◽  
Ammonium Heptamolybdate ◽  
Catalyst Synthesis ◽  
Nimo Catalyst

NiMo catalyst synthesis aimed to make catalyst based on nickel molybdenum Ni(4%-wt) Mo(20%­ wt)γ-Al2O3 by using ammonium heptamolybdate as source of Mo and nickel nitrate as source of Ni, and γ-Al2O3  as a support.  The catalysts are prepared by sequential-dry impregnation method. The preparation parameters that studied are characteristic of support, the ammonium heptamolybdate solution pH, volume of impregnation solution, and stages impregnation of ammonium heptamolybdate solution. The preparation parameter affected the Mo distribution to the support. The inhomogeneous Mo distribution produced MoO crystal in the catalyst. The characterization of catalyst consists of N2 adsorption, XRD, SEM EDAX, and XRF. The results of catalyst characterization are specific surface area, crustallinity of catalyst, deposition metal in pore of support, and catalyst compositions. The NiMo catalyst activity is tested by using coker naphtha feed. The result of activity test is compared with commercial catalyst to know how the performance of catalyst. The composition of NiMo 15 catalyst is 19.43%-b MoO3 dan 2.61%-b NiO. NiMo catalyst with composition 20%-wt Mo and 4%-wt Ni needs support with specific surface area larger than 212 m2/g cat, to get more homogenous Mo distribution. The ammonium heptamolybdate solution pH that is good to use in impregnation to get a homogenous Mo distribution is less or same as 5.Keywords: Hydrotreating, Nimo/γ-Al2O3, ImpregnationAbstrakSintesis katalis NiMo dilakukan untuk membuat katalis hydrotreating dengan komposisi 20%-b MoO3 4%-b NiO/γAl2O3. Sumber Mo dan Ni yang digunakan berasal dari amonium heptamolibdat dan nikel nitrat dengan penyangga γAl2O3.  Preparasi katalis dilakukan dengan menggunakan metode impregnasi kering bertahap. Parameter preparasi yang dipelajari adalah karakteristik penyangga, pH larutan amonium heptamolibdat, volum larutan impregnasi, dan tahapan impregnasi larutan amonium heptamolibdat. Parameter preparasi tersebut mempengaruhi distribusi Mo pada penyangga. Distribusi Mo yang tidak merata akan menghasilkan kristal MoO3 di dalam katalis. Katalis NiMo dikarakterisasi dengan menggunakan analisa adsorpsi N2 difraksi sinar X, SEM EDAX, dan XRF. Hasil karakterisasi katalis berupa luas permukaan spesifik, kristalinitas katalis, gambaran deposisi logam pada pori penyangga, dan komposisi katalis. Katalis NiMo diuji aktivitasnya dengan menggunakan umpan coker nafta. Hasil uji aktivitas dibandingkan dengan katalis komersial untuk mengetahui kinerja dari katalis tersebut. Katalis NiMo 15 memiliki komposisi 19,43%-b MoO3 dan 2,61%-b NiO. Luas permukaan spesifik penyangga yang dibutuhkan untuk membuat katalis NiMo dengan komposisi 20%-b Mo03 dan 4%-b NiO adalah lebih besar dari 212 m2/g kat, agar didapatkan distribusi Mo yang lebih merata. pH larutan amonium heptamolibdat yang baik untuk digunakan dalam impregnasi agar didapatkan distribusi Mo yang merata adalah ≤ 5.Kata Kunci: Hydrotreating, Nimo/ γAl2O3, lmpregnasi

scholarly journals Karakterisasi Katalis Cu-Cr /Kieselguhr

REAKTOR ◽  
2017 ◽  
Vol 5 (1) ◽  
pp. 12
Author(s):  
Galuh Widiyarti
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Program Analysis ◽  
Copper Chromite ◽  
Metal Catalyst ◽  
Impregnation Method ◽  
Active Metal ◽  
Supporting Material ◽  
Catalyst Impregnation

Copper-chromite active metal catalyst was prepared by using impregnation method with kieselguhr (Al2O3SiO2) as supporting material. The content of metal active was 20% with 1:1 proportion of complex metal Cu : Cr. The specific surface area of catalyst gave specific surface area of 2,537 m2/ gram. X-ray Diffraction analysis, shown that active metal of Cu-copper Cu and cristobalite SiO2. Temperature program analysis, shown that reduction temperature of catalyst was 300 0Cusing by Scanning Electronic Microscope (SEM), the morphology of catalyst was determined.Keyword : Copper-Chromite catalyst, impregnation, Kieselguhr

Study on Cu-Based Catalysts for Synthesis of Indole

2011 ◽  
Vol 295-297 ◽  
pp. 668-671 ◽  
Author(s):  
Jun De Xing ◽  
Xiao Fei Jia
Keyword(s):  
Grain Size ◽  
Ethylene Glycol ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Precipitation Method ◽  
Impregnation Method ◽  
Co Precipitation

A series of Cu-based catalysts for the synthesis of indole by the reaction of aniline and ethylene glycol were prepared and characterized by ICP-AES and XRD. The results indicated that the activity and stability of Cu/SiO2 catalyst was increased after adding Zn, Mn, Cr and Fe promoters. Mn promoter was favorable for the dispersion of Cu, Zn, Cr, Fe and enlarged the specific surface area of catalysts. It could be seen that the catalysts prepared by impregnation method had better stability and higher activity than the catalysts prepared by co-precipitation method. The catalysts with small grain size of Cu had higher activity than those with big grain size. Some catalysts showed excellent performances in this reaction.

Effect of Chromium (II, III) Oxide and Cobalt Oxide on the Colour and Fineness of Cement

2016 ◽  
Vol 857 ◽  
pp. 373-376 ◽  
Author(s):  
Lee Chia Wai ◽  
Roszilah Ahmad
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Cobalt Oxide ◽  
Specific Surface Area ◽  
Permeability Test ◽  
Standard Specification ◽  
White Cement ◽  
Oxide Pigment

The objective of this study is to determine the optimum portions of coloured pigments, chromium (I, II) oxide (Cr2O3) and cobalt oxide in producing coloured cement. The fineness (specific surface area - SS) of coloured cement via Blaine permeability test is also determined. The green and grey colours become darker as the percentages of chromium (II, III) oxide and cobalt oxide are increased. The chromium (II, III) oxide coloured cement become coarser as the added portions of chromium (II, III) oxide pigment is increased from 3 to 9 %. For cobalt oxide coloured cement, it becomes finer as the added portions of the cobalt oxide pigment are increased from 3 to 6 %. Results show that the optimum portions of chromium (II, III) oxide and cobalt oxide being added into the white cement in order to produce the colours at the most best is 5%. The Blaine permeability test shows that the values of the specific surface of the coloured cements comply with the Standard Specification.

scholarly journals PREPARATION OF Ni-Mo/MORDENITE CATALYSTS UNDER THE VARIATION OF Mo/Ni RATIO AND THEIR CHARACTERIZATIONS FOR STEARIC ACID CONVERSION

2010 ◽  
Vol 3 (2) ◽  
pp. 80-90
Author(s):  
Wega Trisunaryanti ◽  
Triyono Triyono ◽  
Denty Fibirna A
Keyword(s):  
Stearic Acid ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Gas Adsorption ◽  
Coke Formation ◽  
Reaction System ◽  
Total Pore Volume ◽  
Impregnation Method ◽  
Ammonia Vapour

The preparation of Ni-Mo/Mordenite catalysts with variation of Mo/Ni ratio and their characterizations for conversion of stearic acid have been conducted. The catalysts were prepared by loading a small amount of nickel and/or molybdenum on H-Mordenite (H-Mor) with total metal content = 1 wt% based on the mordenite. The metals was supported on to the mordenite by impregnation method using nickel nitrate and/or ammonium heptamolybdate solution. The Mo/Ni ratio was varied as follows 0/1, 1/0, 1/1, 2/1, and 3/1 produced Ni/Mor, Mo/Mor, Ni1-Mo1/Mor, Ni1-Mo2/Mor and Ni1-Mo3/Mor catalyst respectively. The catalysts were then calcinated with nitrogen, oxidized with oxygen and reduced by hydrogen. The characterizations of catalyst were carried out by measuring Ni and Mo contents using atomic absorbtion spectroscopy (AAS), acidity by ammonia vapour adsorption, specific surface area and pore size distribution by nitrogen gas adsorption (NOVA-1000). The catalyst characters on conversion of stearic acid were performed in a flow reaction system at 4000C under hydrogen stream (10 mL/min). The AAS analyses showed that the metal impregnated on to the H-Mor sample were consistent to the initial metal concentrations. The loading of Ni and/or Mo enhanced the acidity, however decreased the specific surface area and total pore volume of the H-Mor sample. The higher the acidity the higher the conversion of stearic acid and the lower the coke formation. The other catalyst characters gave the variation effects toward the stearic acid conversion. The conversions of stearic acid were 34,52%,  43,33%, 65,10%, 80,10%, 86,42% and 95,72% produced by Ni1-Mo3/Mor, H-Mor, Mo/Mor, Ni/Mor, Ni1-Mo2/Mor and Ni1-Mo1/Mor catalyst, respectively.   Keywords: Ni-Mo/Mordenite, impregnation, stearic acid, Ni1-Mo1/Mordenite

scholarly journals PENGARUH RASIO MOLAR MINYAK JELANTAH DENGAN METANOL DAN SUHU REAKSI DALAM REAKSI TRANSESTERFKASI TERKATALIS CaO/ZEOLIT ALAM TERHADAP YIELD BIODIESEL

Jurnal Kimia ◽  
2016 ◽  
Author(s):  
Ana Malia ◽  
Putu Suarya ◽  
Ida Ayu Raka Astiti Asih ◽  
I Made Wisnu Adhi Putra
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Natural Zeolite ◽  
Transesterification Reaction ◽  
Molar Ratio ◽  
High Yield ◽  
Co2 Absorption ◽  
Impregnation Method ◽  
Bet Method

The research of transesterification reaction catalyzed by CaO/natural zeolite has been carried out. This work was aimed to obtain the high yield of biodiesel. The supporting process of CaO on natural zeolite (CaO/ZAA) was done by using wet impregnation method and characterization of CaO/ZAA was performed using XRD, FTIR and the determination of specific surface area of natural zeolite as CaO supporter was performed by BET method. This research aims to study the influence of transesterification reaction which was executed by varying molar ratio of oil to methanol and reaction temperature. Analysis of functional groups and minerals using FTIR and XRD, respectively, showed no significant changes before and after the impregnation of CaO on natural zeolites. CaO supported on natural zeolite was undetected by FTIR. Instead, it was detected by the vibration of carbonate groups as the result of the CO2 absorption by CaO and the result of surface area analysis using BET method showed that the greater the size of natural zeolite, the smaller the specific surface area of catalyst. The result analysis using BET method showed that the spesific surface area of 200 mesh sized natural zeolite as CaO supporter was 9.993 m2/g. The simple gravimetric test revealed that  the amount of CaO supported on 200 mesh sized natural zeolite was 0.2155 g/g. It was concluded that CaO/ZAA 200 mesh was the most suitable catalyst which was then used in the production of biodiesel. The transesterification result showed that the highest biodiesel yield of 98.34% was gained at molar ratio of oil to methanol of 1:15 and at the temperature of 60 oC. The GC-MS analysis indicated that the main components of the biodiesel were methyl palmitate and methyl oleate.

scholarly journals Samarium Promoted Ni/Al2O3 Catalysts for Syngas Production from Glycerol Pyrolys

2016 ◽  
Vol 11 (2) ◽  
pp. 238 ◽  
Author(s):  
Mohd Nasir Nor Shahirah ◽  
Bamidele V. Ayodele ◽  
Jolius Gimbun ◽  
Chin Kui Cheng
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Fixed Bed Reactor ◽  
Ni Catalyst ◽  
Impregnation Method ◽  
Glycerol Conversion ◽  
Product Ratio ◽  
Syngas Production ◽  
Bet Specific Surface Area

<p>The current paper reports on the kinetics of glycerol reforming over the alumina-supported Ni catalyst that was promoted with rare earth elements. The catalysts were synthesized via wet impregnation method with formulations of 3 wt% Sm-20 wt% Ni/77 wt% Al<sub>2</sub>O<sub>3</sub>. The characterizations of all the as-synthesized catalysts were carried out, viz.  BET specific surface area measurements, thermogravimetri analysis for temperature-programmed calcination studies, FESEM for surface imaging, XRD to obtain diffraction patterns, XRF for elemental analysis, etc.. Reaction studies were performed in a stainless steel fixed bed reactor with reaction temperatures set at 973, 1023 and 1073 K employing weight hourly space velocity (WHSV) of 4.5×10<sup>4</sup> mL g<sup>-1</sup> h<sup>-1</sup>. Agilent GC with TCD capillary column was used to analyze gas compositions. Results gathered showed that the BET specific surface area was 2.09 m<sup>2</sup>.g<sup>-1</sup> for the unpromoted Ni catalyst while for the promoted catalysts, was 2.68 m<sup>2</sup>.g<sup>-1</sup>. Significantly, the BET results were supported by the FESEM images which showed promoted catalysts exhibit smaller particle size compared to the unpromoted catalyst. It can be deduced that the promoter can increase metal dispersion on alumina support, hence decreasing the size of particles. The TGA analysis consistently showed four peaks which represent water removal at temperature 373-463 K, followed by decomposition of nickel nitrate to produce nickel oxide. From reaction results for Sm promotion showed glycerol conversion, X<sub>G</sub> of 27% which was 7% higher than unpromoted catalyst. The syngas productions were produced from glycerol decomposition and created H<sub>2</sub>:CO product ratio which always lower than 2.0. The H<sub>2</sub>:CO product ratio of 3 wt% Sm promoted Ni/Al<sub>2</sub>O<sub>3</sub> catalyst was 1.70 at reaction temperature of 973 K and glycerol partial pressure of 18 kPa and suitable enough for Fischer-Tropsch synthesis.  Copyright © 2016 BCREC GROUP. All rights reserved</p><p><em>Received: 22<sup>nd</sup> January 2016; Revised: 1<sup>st</sup> February 2016; Accepted: 17<sup>th</sup> February 2016</em></p><strong>How to Cite:</strong> Shahirah, M.N.N., Ayodele, B.V., Gimbun, J., Cheng, C.K. (2016). Samarium Promoted Ni/Al<sub>2</sub>O<sub>3</sub> Catalysts for Syngas Production from Glycerol Pyrolysis. <em>Bulletin of Chemical Reaction Engineering &amp; Catalysis</em>, 11 (2): 238-244 (doi:10.9767/bcrec.11.2.555.238-244)<p><strong>Permalink/DOI:</strong> http://dx.doi.org/10.9767/bcrec.11.2.555.238-244</p>

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