scholarly journals Pembuatan Katalis Pd-Ce/γ –Al2O3 dan Uji Aktivitas terhadap Oksidasi Metana

1999 ◽  
Vol 2 (3) ◽  
pp. 104-111
Author(s):  
Ahmad Suseno ◽  
Triyono Triyono ◽  
Bambang Setiaji
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
Pore Volume ◽  
Pore Radius ◽  
Flow Reactor ◽  
Chloride Salt ◽  
Oxidation Of Methane ◽  
Sorption Method ◽  
Determine Surface Area ◽  
Products Of Reaction

Effects of Ce addition on Pt/γ - Al2O3 catalysts preparation and their catalytic activity on oxidation of methane have been investigated. In this study, the catalysts were prepared by impregnating chloride salt solution of palladium and sulphate salt of cerium on γ-AI2O3 support. Characterization of catalysts was conducted by gas sorption method to determine surface area, pore radius and pore volume. The test of catalytic activity on oxidation of methane was carried out in a flow reactor system at a temperature range from 350°C to 600°C. Products of reaction were analysed by non-dispersive IR spectroscopy. It was observed that the surface area, pore radius and pore volume decrease with the addition of cerium. The results of oxidation process showed that Pd-Ce/γ-Al2O3 catalyst can be used for oxidation of methane up to 90.62% conversion

scholarly journals Surface and Catalytic Properties of γ-Irradiated Cr2O3/Al2O3 Solids

1997 ◽  
Vol 15 (6) ◽  
pp. 465-476 ◽  
Author(s):  
G.A. El-Shobaky ◽  
A.M. Ghozza ◽  
G.M. Mohamed
Keyword(s):  
Catalytic Activity ◽  
Co Oxidation ◽  
Surface Area ◽  
Pore Volume ◽  
Active Sites ◽  
Catalytic Properties ◽  
Total Pore Volume ◽  
Bet Surface Area ◽  
Two Samples ◽  
Γ Rays

Two samples of Cr2O3/Al2O3 were prepared by mixing a known mass of finely powdered Al(OH)3 with a calculated amount of CrO3 solid followed by drying at 120°C and calcination at 400°C. The amounts of chromium oxide employed were 5.66 and 20 mol% Cr2O3, respectively. The calcined solid specimens were then treated with different doses of γ-rays (20–160 Mrad). The surface and catalytic properties of the different irradiated solids were investigated using nitrogen adsorption at −196°C and the catalysis of CO oxidation by O2 at 300–400°C. The results revealed that γ-rays brought about a slight decrease in the BET surface area, SBET (15%), and in the total pore volume, Vp (20%), of the adsorbent containing 5.66 mol% Cr2O3. The same treatment increased the total pore volume, Vp (36%), and the mean pore radius, r̄ (43%), of the other adsorbent sample without changing its BET surface area. The catalytic activities of both catalyst samples were found to increase as a function of dose, reaching a maximum value at 80–160 Mrad and 40 Mrad for the solids containing 5.66 and 20 mol% Cr2O3, respectively. The maximum increase in the catalytic activity measured at 300°C was 59% and 100% for the first and second catalyst samples, respectively. The induced effect of γ-irradiation on the catalytic activity was an increase in the concentration of catalytically active sites taking part in chemisorption and in the catalysis of CO oxidation by O2 without changing their energetic nature. This was achieved by a progressive removal of surface hydroxy groups during the irradiation process.

scholarly journals Syngas Production via CO2 Reforming of Methane Over SrNiO3 and CeNiO3 Perovskites

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2928
Author(s):  
Naushad Ahmad ◽  
Fahad Alharthi ◽  
Manawwer Alam ◽  
Rizwan Wahab ◽  
Salim Manoharadas ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Active Sites ◽  
Catalyst Deactivation ◽  
Dry Reforming Of Methane ◽  
Volume Number ◽  
Syngas Production

The development of a transition-metal-based catalyst with concomitant high activity and stability due to its distinguishing characteristics, yielding an abundance of active sites, is considered to be the bottleneck for the dry reforming of methane (DRM). This work presents the catalytic activity and durability of SrNiO3 and CeNiO3 perovskites for syngas production via DRM. CeNiO3 exhibits a higher specific surface area, pore volume, number of reducible species, and nickel dispersion when compared to SrNiO3. The catalytic activity results demonstrate higher CH4 (54.3%) and CO2 (64.8%) conversions for CeNiO3, compared to 22% (CH4 conversion) and 34.7% (CO2 conversion) for SrNiO3. The decrease in catalytic activity after replacing cerium with strontium is attributed to a decrease in specific surface area and pore volume, and nickel active sites covered with strontium carbonate. The stability results reveal the deactivation of both the catalysts (SrNiO3 and CeNiO3) but SrNiO3 showed more deactivation than CeNiO3, as demonstrated by deactivation factors. The catalyst deactivation is mainly attributed to carbon deposition and these findings are verified by characterizing the spent catalysts.

CuO/CeO2 and CuO/PrO2-CeO2 Catalysts for Preferential Oxidation of CO

2013 ◽  
Vol 773 ◽  
pp. 601-605 ◽  
Author(s):  
Zhi Jun Zhao ◽  
Ruo Yu Wang ◽  
Qian Long Zhao ◽  
En Peng Wang ◽  
Hai Quan Su ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Hydrothermal Method ◽  
Surface Area ◽  
Pore Volume ◽  
Crucial Role ◽  
Textural Properties ◽  
Bet Surface Area ◽  
Oxidation Of Co ◽  
Preferential Oxidation Of Co ◽  
Adsorption Desorption

The CuO/CeO2and CuO/PrO2-CeO2catalysts were prepared by the hydrothermal method, and characterized via XRD, SEM and N2adsorption-desorption techniques. The study shows that the BET surface area and pore volume of the CuO/PrO2-CeO2catalysts increase with the increase of praseodymium content. The CuO/CeO2catalyst presents higher catalytic activity in compare with the CuO/PrO2-CeO2catalysts although the addition of praseodymium promotes textural properties of the CuO/CeO2catalysts, and it proves that the interaction of CuO and CeO2has a crucial role in CO-PROX.

Preparation of Au and Au-Ce Catalysts Supported on Acid-Activated Bentontie and its Catalytic Performance

2011 ◽  
Vol 287-290 ◽  
pp. 1704-1707
Author(s):  
Rong Bin Zhang ◽  
Liu Jing Yao ◽  
Yan Ju
Keyword(s):  
Catalytic Activity ◽  
Co Oxidation ◽  
Surface Area ◽  
Pore Volume ◽  
Catalytic Performance ◽  
Substantial Improvement ◽  
Au Catalyst ◽  
Activated Bentonite

Acid-activated by H2SO4was applied to modify bentonite. Acid-activated bentonite supported Au catalyst was prepared by deposition-precipitation and compared with SiO2supported one. CTAB was used to modify the surface of acid-activated bentonite. Au-Ce/bentontie catalyst was prepared by adding Ce into catalyst as assistant. CO oxidation was used to evaluate the catalytic activity of samples. These samples were characterized by BET, XRD, ICP and CO-TPD. The activity results showed that Au/Bentonite was more active than Au/SiO2. The BET results showed that the surface area and pore volume of acid-activated bentontie had a substantial improvement. Using the bentontie acid-activated by 30wt%H2SO4as supporter，the Au-Ce catalyst has a better catalytic performance than Au catalyst.

scholarly journals Biochar from Slow Catalytic Pyrolysis of Spirulina platensis Residue: Effects of Temperature and Silica-Alumina Catalyst on Yield and Characteristics

2020 ◽  
Vol 14 (2) ◽  
pp. 137
Author(s):  
Siti Jamilatun ◽  
Ilham Mufandi ◽  
Arief Budiman ◽  
Suhendra Suhendra
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Pore Volume ◽  
Spirulina Platensis ◽  
Catalytic Pyrolysis ◽  
Pore Radius ◽  
Fixed Bed ◽  
Total Pore Volume ◽  
Alumina Catalyst ◽  
Silica Alumina

The use of biochar varies on its ability as an adsorbent which adsorbs liquid or gas molecules. Biochar from Spirulina platensis residue (SPR) as an energy source, as its richness in nutrients, can be used as fertilizer and maintain water resources in plantations. Biochar can be used as an intermediary for the synthesis of nanotubes, activated carbon, carbon black, and carbon fiber. One of the essential things to be considered in the application of activated carbon from SPR is char’s characteristics. This study aimed to obtain data on the biochar and components from the pyrolysis of Spirulina platensis residue. The study was conducted in a fixed-bed reactor with electric heaters with a variety of temperatures (300-700 ⁰C) and the amount of silica-alumina catalyst (0-20%). The biochar weight was obtained by weighing the char formed at the end of the pyrolysis. The char characteristics were obtained by the surface area, total pore volume, and pore size analysis. Based on the study results, the relationship between temperature and the amount of catalyst on the characteristics of biochar was studied. The higher the pyrolysis temperature, the less biochar. Also, the use of catalysts can reduce the amount of biochar. The higher the temperature, the higher the surface area and the total pore volume while the pore radius was reduced. The optimum condition for maximum biochar yield in non-catalytic pyrolysis at a temperature of 300 ⁰C was 49.86 wt.%. The surface area, the total pore volume, and the pore radius at 700 ⁰C catalytic pyrolysis with 5% silica-alumina was obtained as 36.91 m2/g, 0.052 cm3/g, and 2.68 nm, respectively.Keywords: biochar; pore radius; silica-alumina; surface area; total pore volumeA B S T R A KPenggunaan biochar bervariasi pada kemampuannya sebagai adsorben dalam menjerap molekul cairan atau gas. Biochar dari residu Spirulina platensis merupakan sumber energi, karena kaya akan unsur hara, dapat digunakan sebagai pupuk dan pemeliharaan sumber daya air di perkebunan. Biochar dapat juga digunakan sebagai perantara untuk sintesis nanotube, karbon aktif, carbon black, dan serat karbon. Salah satu hal penting yang harus diperhatikan dalam aplikasi karbon aktif dari SPR adalah karakteristik arang. Penelitian ini bertujuan untuk mendapatkan data biochar dan komponen dari pirolisis residu Spirulina platensis. Penelitian dilakukan di reaktor fixed-bed dengan pemanas listrik dengan variasi suhu (300-700 ⁰C) dan jumlah katalis silika-alumina (0-20%). Berat biochar diperoleh dengan cara menimbang arang yang terbentuk pada akhir pirolisis. Sedangkan karakteristik arang diperoleh dari analisis luas permukaan, volume pori total, dan ukuran pori. Berdasarkan hasil studi hubungan antara suhu dan jumlah katalis terhadap karakteristik biochar yang telah diteliti, semakin tinggi suhu pirolisis maka biochar semakin sedikit. Selain itu, penggunaan katalis dapat mengurangi jumlah biochar. Sebaliknya, semakin tinggi suhu semakin besar luas permukaan, dan volume pori total serta radius pori-pori semakin berkurang. Kondisi optimum untuk biochar maksimum pada pirolisis non katalitik pada suhu  300 ⁰C adalah 49,86 wt.%. Luas permukaan, total volume pori, dan radius pori pada suhu 700 ⁰C untuk pirolisis katalitik silika-alumina 5% diperoleh masing-masing sebesar 36,91 m2/g, 0,052 cm3/g, dan 2,68 nm.Kata kunci: biochar; luas permukaan; radius pori; silika-alumina; total volume pori  

scholarly journals The Intercalation of Copper into Active Carbon and Its Application as a Catalyst for n-Amylalcohol Dehydration

2010 ◽  
Vol 1 (1) ◽  
pp. 23-29
Author(s):  
Rusman Rusman ◽  
Iip Izul Falah ◽  
RHA. Sahirul Alim
Keyword(s):  
Surface Area ◽  
Active Carbon ◽  
Pore Volume ◽  
Flow Reactor ◽  
Total Pore Volume ◽  
Heating Time ◽  
Hydrogen Gas ◽  
Volume Distribution ◽  
Cu Content ◽  
Atomic Adsorption Spectroscopy

The intercalation of CuCl2 salts into active carbon and its activity as catalyst on dehydration of n-amylalcohol has been investigated. In this research, the intercalation was conducted by reacting CuCl2 powder with active carbon and Cl2 gas at 3 atm, temperature 575 °C, at various heating time. This process was then followed by the reduction in the flowing hydrogen gas. Characterization of intercalation product was conducted by gas sorption method to determine surface area, pore radius, and pore volume distribution, and atomic adsorption spectroscopy (AAS) was used to determine the content of Cu metal. The test of catalytic activity on dehydration reaction of n-amylalcohol, was carried out in a flow reactor system at various temperatures. The results showed that the surface area and total pore volume increase with the longer time of intercalation process, and followed by increasing Cu content on active carbon. It was showed further that catalyst with highest Cu content, and the largest of both of surface area and total pore volume gives the best performance.

scholarly journals Chemical and Physical Properties of the Al1-xFexPO4 System Prepared by the Coprecipitation Method. II. Surface Acidity, Textural Properties and Catalytic Activity

2002 ◽  
Vol 20 (8) ◽  
pp. 741-755 ◽  
Author(s):  
F.Sh. Mohamed
Keyword(s):  
Catalytic Activity ◽  
Calcination Temperature ◽  
Pore Volume ◽  
Pore Radius ◽  
Surface Acidity ◽  
Total Pore Volume ◽  
Textural Properties ◽  
Coprecipitation Method ◽  
Temperature Variations ◽  
Kinetics Of

A coprecipitation method for the preparation of Al1-xFexPO4 catalysts with x (or Fe/P ratio) = 0.0, 0.2, 0.4, 0.6 and 0.8 was developed. The samples were calcined at temperatures within the range 200–800°C. The surface structure, cumulative acidity, textural properties, and the catalytic activity and selectivity of the prepared samples towards isopropanol and cyclohexane conversion were studied using different techniques. The results showed that the freshly calcined samples consisted of an amorphous phase, a quartz-type and a tridymite-type phase depending on the calcination temperature. The total surface acidity decreased with FePO4 content or calcination temperature. Variations in the Fe/P ratio and the calcination temperature led to changes in both the surface area and total pore volume of the Al1-xFexPO4 samples. Increases in the Fe/P ratio and increasing calcination temperature led to increases in the pore radius. The catalytic activity and selectivity were significantly affected as the structures of the Al1-xFexPO4 catalysts varied. The kinetics of the reaction were also studied.

scholarly journals Methanation Activity in Relation to the Textural and Catalytic Parameters of Ni/Al2O3 Catalysts

1998 ◽  
Vol 16 (5) ◽  
pp. 367-380 ◽  
Author(s):  
S.E. Samra ◽  
S.A. El-Hakam ◽  
A.M. Youssef
Keyword(s):  
Surface Area ◽  
Pore Radius ◽  
Flow Reactor ◽  
Textural Properties ◽  
Nitrogen Adsorption ◽  
Impregnation Technique ◽  
Catalytic Material ◽  
Materials Used ◽  
Consequent Increase ◽  
Methanation Activity

A range of NiO/Al2O3, solids (4.0–12.0 wt% Ni) was prepared by the impregnation technique. The textural properties of these solids were determined from nitrogen adsorption measurements at 77 K. Reduction of the solids with hydrogen was carried out 650, 675, 700 and 725 K. Some catalytic parameters for these reduced materials were determined from studies of the adsorption of hydrogen at 400 K. The methanation of carbon monoxide over these reduced materials used as catalysts was followed between 550 K and 600 K using a steady-state flow reactor. The surface area of the NiO/Al2O3 solids decreased and their mean pore radius increased with increasing content of NiO. Increasing the temperature employed for their reduction led to increased diffusion of Ni atoms to the surface with a consequent increase in their catalytic activity. A direct relationship was found between % methanation and the surface area of the reduced catalytic material expressed as m2/g (catalyst).

Sign in / Sign up

Export Citation Format

Share Document