Examining a catalyst sample for demercaptanization process

2019 ◽  
Vol 37 (24) ◽  
pp. 2391-2396
Author(s):  
Javad Alaei Kadijani ◽  
Amirmasoud Zolfaghari
Keyword(s):  
Catalyst Sample

scholarly journals Influence of Impurity Dissolution on Surface Properties and NH3-SCR Catalytic Activity of Rare Earth Concentrate

Minerals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 246
Author(s):  
Zhang ◽  
Zhu ◽  
Zhang ◽  
Li ◽  
Luo ◽  
...  
Keyword(s):  
Rare Earth ◽  
Active Sites ◽  
Catalytic Effect ◽  
Catalytic Reduction ◽  
Weak Acid ◽  
Active Components ◽  
Catalyst Sample ◽  
Nh3 Scr ◽  
O2 Concentration ◽  
Alkali Leaching

Impurity removal and modification of rare earth concentrate powder were conducted by roasting weak acid-weak alkali leaching to obtain the active components of denitrification catalysts. NH3 selective catalytic reduction catalyst samples were prepared by mixing and kneading with pseudo-γ-Al2O3 boehmite as carrier. The results showed that the Ce7O12 content in the active component samples increased and dispersed more evenly. The grain size of the samples was refined, the specific surface area increased, and the active sites exposed more. Ce coexists in the form of Ce3+ and Ce4+. Fe coexists in the form of Fe3+ and Fe2+, but Fe3+ is abundant. Some Ce, La, Nd, Pr, Fe, Mn, and other components formed solid melts during preparation, which increased the synergistic catalytic effect. The denitrification efficiency of the catalyst sample was 92.8% under the conditions of reaction temperature 400 °C, NO content was 600 ppm, NH3/NO ratio was 1.5, and O2 concentration was 4%.

Analisis Struktur dan Spesies Permukaan Terhadap Kereaktifan Mangkin Oksida Mangan–Timah

2012 ◽  
Author(s):  
Mohd. Tahir Ahmad ◽  
Wan Azelee Wan Abu Bakar ◽  
Nor Aziah Buang
Keyword(s):  
Manganese Oxides ◽  
Fixed Bed ◽  
Xrd Analysis ◽  
Catalytic Performance ◽  
Impregnation Method ◽  
Catalyst Sample ◽  
Calcination Temperatures ◽  
Composition Ratios ◽  
The Relationship ◽  
Micro Reactor

Oksida timah (IV) dengan kehadiran bahan pendop memperlihatkan pelbagai aktiviti yang menarik untuk dikaji dengan mendalam. Dalam kajian ini oksida timah (IV) didopkan dengan Mn(II) dan Mn(IV) pada pelbagai nisbah komposisi dan suhu pengkalsinan menggunakan kaedah pengisitepuan. Bagi melihat aktiviti pemangkinan, sampel mangkin diuji menggunakan sistem reaktor mikro padatan tetap yang menghampiri keadaan sebenar ekzos kenderaan bermotor. Hasil ujian menunjukkan sampel mangkin yang didopkan dengan Mn(II) pada nisbah komposisi 40:60 berpotensi sebagai mangkin dua arah yang setanding dengan mangkin komersil, Pt/AI2O3 dan Hopcalite (CuMn2O4). Pengoksidaan lengkap 100% (T100) berlaku pada suhu yang rendah iaitu T100 = 100°C bagi gas CO dan T100 = 300°C bagi gas propana. Bagi memahami kaitan struktur dan keupayaan pemangkinan sampel mangkin, dua teknik pencirian dilakukan iaitu XPS dan XRD. Pencirian melalui teknik XPS mengenalpasti oksida mangan wujud dengan nombor pengoksidaan +2 dan +3 pada suhu pengkalsinan 400 dan 600°C. Kewujudan nombor pengoksidaan tersebut disahkan melalui teknik XRD iaitu bagi oksida mangan disumbang oleh Mn2O3 dan spinel Mn3O4. Didapati aktiviti pemangkinan yang terbaik bagi sampel mangkin ialah apabila sampel mangkin berada dalam percampuran kedua–dua nombor pengoksidaan tersebut. Daripada teknik XRD juga didapati darjah kehabluran sampel mangkin meningkat apabila suhu pengkalsinan ditingkatkan. Kata kunci: Aktiviti pemangkinan; XPS dan XRD Tin(IV) oxide when doped with other metal oxides exhibit interesting activities to be studied further. In this research, tin(IV) oxide was doped with Mn(II) and Mn(IV) at various composition ratios and calcination temperatures using an impregnation method. The catalytic performance of the prepared sample were investigated using a fixed bed micro-reactor system which resembled the actual exhaust gas condition. For catalyst sample doped with Mn(II) 40:60, the catalytic results have shown their potential as 2–way catalyst that are comparable with the commercial catalyst (Pt/AI2O3 and Hopcalite (CuMn2O4). Catalyst sample gave a 100% conversion (T100) at a low temperature of T100 = 100°C for CO and T100 of 300 for C3H8. To verify the relationship between the structures of the catalyst sample with their catalytic capabilities, characterisation analysis by XPS and XRD were performed. XPS analysis recalled the existence of manganese oxides with oxidation numbers of +2 and +3 at calcination temperatures of 400 and 600°C. This finding is supported by XRD analysis which showed that the manganese oxide was contributed by Mn2O3 and spinel Mn3O4. Therefore the best catalytic activities could be achieved with a catalyst sample prepared under a mixture of the two oxidation numbers. More over from the XRD technique, the degree of crystalinity of the catalyst sample increase as the calcination temperature increases. Key words: Catalytic activity; XPS and XRD

Modification HKUST-1 as a catalyst for the reduction of 4-nitrophenol

2021 ◽  
Vol 10 (4) ◽  
pp. 27-38
Author(s):  
Ha Bui Thi Thanh ◽  
Duong Le Van ◽  
Duong Le Ngoc ◽  
Hung Ta Ngoc ◽  
Anh Nguyen Le ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
High Efficiency ◽  
Metal Organic Framework ◽  
Experimental Conditions ◽  
Catalyst Sample ◽  
Metal Organic ◽  
Efficiency Conversion ◽  
Organic Framework

HKUST-1 (MOF-199), a metal-organic framework material is synthesized from Cu(OH)2 and modified by Pt. The prepared catalysts were used to reduce 4-nitrophenol (4-NP) into 4-aminophenol (4-AP). Featured results of the catalysts by XRD, SEM, TEM, FTIR, BET, DTA/TGA... showed that metal modified process with reduced agent ethylene glycol had high efficiency, with modified yield up to 90 %. Under our experimental conditions, the catalysts based HKUST-1, containing Pt had high efficiency; conversion was greater than 93 % in reduced reaction of 4-NP. Thus, the catalyst sample contained 2% Pt was the most suitable for the reduction with conversion gained 99,4 % after 250s.

Relation between Cell Density and PM Content Investgation of Three-Way Catalyst

2012 ◽  
Vol 624 ◽  
pp. 291-294
Author(s):  
Wei Jun Zhang ◽  
Jin Hu ◽  
Hong Luo ◽  
Li Shen ◽  
Hua Tan ◽  
...  
Keyword(s):  
Cell Density ◽  
Noble Metal ◽  
Metal Content ◽  
Aging Treatment ◽  
Catalyst Stability ◽  
Catalyst Structure ◽  
Catalyst Sample ◽  
Noble Metal Catalysts ◽  
Precious Metal Content ◽  
Three Way Catalyst

In this paper, Pd/Rh series catalyst substrate samples were prepared at the different cell density, with different volume. The fresh catalyst aging treatment. And Catalysts test by light-off factor (LOF). The results tested demonstrated that, it can achieve equal performance levels with the cell density is 600cpsi that the catalyst sample of the cell density is 400cpsi with the precious metal content for the 1.2g/L. This is more efficient for low content of noble metal catalysts. This work is still importantly to promoted catalyst stability, that the catalyst structure is optimized. And it can be used as the interaction between cell density and noble metal content of catalysts.

Modification of Mesoporous CaZr4(PO4)6 and its Acid Catalytic Performance

2011 ◽  
Vol 396-398 ◽  
pp. 1851-1855
Author(s):  
Tian Si ◽  
Lin Hua Zhu
Keyword(s):  
Surface Acidity ◽  
Sol Gel ◽  
Acid Catalyst ◽  
Catalytic Performance ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
Catalyst Sample ◽  
New Type ◽  
Temperature Programmed ◽  
N2 Sorption

A series of new type acid catalyst samples based on mesoporous CaZr4(PO4)6(CZP) belonging to NZP family synthesized by sol-gel method was obtained by Al, La, B incorporation in CZP or by heteropoly acid H3PW12O7•xH2O(HPW) loading on CZP, and their acid catalytic activity and selectivity were investigated by using α-pinene isomerization as a probe reaction. The phase, pore structure and surface acidity of the catalyst samples were characterized by X-ray diffraction (XRD), N2 sorption and NH3 temperature programmed desorption (NH3-TPD) respectively. The results showed that the surface acidity of CZP modified by elements incorporation and HPW loading was improved in a different extent. The conversion of α-pinene at 150 °C reached to 41 % over the catalyst sample noted as Al-CZP-0.15 in which the mole ratio of Al to Zr was 0.15. Under the same reaction conditions, the conversion of α-pinene was above 95 % over the CZP supported with 20-30wt. %HPW.

scholarly journals A novel optode sensor for the determination of palladium(II) in water and a hydrogenation catalyst

2009 ◽  
Vol 74 (3) ◽  
pp. 311-315 ◽  
Author(s):  
Hossein Tavallali ◽  
Pisheh Jahromi
Keyword(s):  
Response Time ◽  
Aqueous Solutions ◽  
Optical Sensor ◽  
Color Change ◽  
Limit Of Detection ◽  
Linear Range ◽  
Hydrogenation Catalyst ◽  
Catalyst Sample ◽  
Dynamic Linear Range

A novel optical sensor was established to determine palladium(II) based on the immobilization of 1-(2-pyridylazo)-2-naphthol (PAN) on a triacetylcellulose membrane. Palladium ions react with the immobilized PAN and cause a decrease in the absorbance of the membrane at 469 nm. The response time of the optode was 8-10 min depending on the concentration of Pd(II) ions. This sensing phase had a dynamic linear range of 0.10-12.0 ?g ml-1 palladium ions with a limit of detection of 65 ng ml-1. The sensor can readily be regenerated using an ethylenediamine solution. The sensor could be fully regenerated, and the color change was fully reversible. The method was successfully applied for the determination of Pd(II) in synthetic aqueous solutions and in a hydrogenation catalyst sample.

Influence of catalyst, sample weight, and digestion conditions on Kjeldahl nitrogen

1993 ◽  
Vol 24 (13-14) ◽  
pp. 1609-1616 ◽  
Author(s):  
Eric H. Simonne ◽  
J. Benton Jones ◽  
Harry A. Mills ◽  
Doyle A. Smittle ◽  
Chris G. Hussey
Keyword(s):  
Sample Weight ◽  
Catalyst Sample ◽  
Kjeldahl Nitrogen

Nonlinear behavior during NO 2 hydrogenation on a nanosized Pt-Rh catalyst sample

2017 ◽  
Vol 412 ◽  
pp. 564-570 ◽  
Author(s):  
Cédric Barroo ◽  
Yannick De Decker ◽  
Luc Jacobs ◽  
Thierry Visart de Bocarmé
Keyword(s):  
Nonlinear Behavior ◽  
Catalyst Sample ◽  
Rh Catalyst

scholarly journals OXIDATION OF ALCOHOLS OVER CERIUM-OXIDE CATALYST: CORRELATION BETWEEN THE ACTIVATION ENERGY OF THE REACTION AND THE CHEMICAL SHIFT δ (R13 COH)

2019 ◽  
Vol 85 (8) ◽  
pp. 66-72
Author(s):  
Volodymyr Brei
Keyword(s):  
Activation Energy ◽  
Chemical Shift ◽  
Hydrate Formation ◽  
Alcohol Oxidation ◽  
Sweep Rate ◽  
Electronic Density ◽  
Catalyst Sample ◽  
Mass Spec ◽  
Oxidation Of Alcohols ◽  
Aldehydes And Ketones

The oxidation of thirteen alcohols over sup-ported CeO2/Al2O3 catalyst with 10 wt.% of CeO2 have been studied using a desorption mass-spec-trometry technique. A catalyst sample 4–6 mg in quartz cuvette was evacuated at 100 0C, cooled to room temperature, and then adsorption of a alco-hol was provided. After vacuumation of alcohol excess, the TPR profiles of products of alcohol oxidation were recorded at sweep rate 2 a.u.m./sec and heating rate of 15 0C/min using MX-7304A monopole mass- spectrometer. Identification of formed aldehydes and ketones was provided on the bases of their characteristic ions in obtained mass-spectra, namely, acetaldehyde (m/e = 29, 44); pro-panal (29, 58); acetone (43, 58); butanal (44, 43); methyl propanal (43, 41, 72), 2-butanon (43, 72); methoxyacetone (45, 43); cyclohexanone (55); ace-tophenone (105, 77); benzaldehyde (77, 106). It was shown that the oxidation of several alcohols pro-ceeds in a wide temperature interval from 130 to 280 0C. So, peak of formaldehyde formation from me-thanol adsorbed on CeO2/Al2O3 is observed at 280 0C whereas peaks of methyl glyoxal and water formation from adsorbed hydroxyacetone are re-corded at 135 0 C. The linear correlation between activation energy of reaction and chemical shift δ (R13COH) of studied alcohols was found as Ea= 183 –1.4δ (kJ/mol). Respectively, the maximum oxi-dation rate, for instance, for methanol (50 ppm) is observed at 280 0C, for ethanol (58 ppm) at 215 0C, for n-butanol (62 ppm) at 200 0C, for n-propanol (64 ppm) at 190 0C, for 2-butanol (69 ppm) at 160 0C, for hydroxyacetone (69 ppm) at 135 0C, and for 1-phenylethanol (70 ppm) at 130 0C. Thus, ability of alcohols to oxidation decreases with increase of their electronic density on carbon atom of alcohol group in following order: 1-phenyl ethanol ≈ hyd-roxyacetone ≈ cyclohexanol > allyl alcohol ≈ 2-bu-anol ≈ i-butanol ≈ i-propanol > methoxypropanol-2 ≈ n-propanol ≈ n-butanol ≈ benzyl alcohol ≈ ethanol >> methanol. On an example of ethanol, the scheme of alcohol oxidation on ceria that assumes the addition of atomic oxygen to C–H bond of alcoho-lic group with intermediate acetaldehyde hydrate formation is discussed.

Reduction of 4-nitrophenol to 4-aminophenol using Pt/HKUST-1 catalyst

2021 ◽  
Vol 10 (4) ◽  
pp. 110-116
Author(s):  
Ha Bui Thi Thanh ◽  
Duong Le Van ◽  
Hung Ta Ngoc ◽  
Hai Dinh Thi Thanh ◽  
Duong Pham Dai ◽  
...  
Keyword(s):  
Reaction Rate ◽  
Good Stability ◽  
High Concentration ◽  
Catalyst Sample

The catalyst Pt/HKHUST-1 was used for synthesis 4-aminophenol (4-AP) by reducsion 4-nitrophenol (4-NP). Factors that affected to the reaction were tested: ratio 4-NP/NaBH4, temperature and time of the reaction. Changing the ratio of 4-NP/NaBH4 in the direction of increasing NaBH4, the reaction rate increases. However, it is acceptable to reduce the reaction rate when synthesizing with high concentration of reactants. The 4-AP synthesis is performed with ratio 4-NP/NaBH4 = 1/5, suitable time and temperature for this reaction is 60 minutes and 15 oC. The catalyst sample containing 2% Pt on HKUST-1 material was used to synthesize 4-AP with the yield of 65.3% (average 64.2%), the catalyst has good stability, can reused many times. The purity of 4-AP after refining was 99 %.

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