scholarly journals Chemical Reduction Behavior of Zirconia Doped to Nickel at Different Temperature in Carbon Monoxide Atmosphere

2019 ◽  
Vol 20 (1) ◽  
pp. 105
Author(s):  
Norliza Dzakaria ◽  
Maratun Najiha Abu Tahari ◽  
Fairous Salleh ◽  
Alinda Samsuri ◽  
Masitah Abdul Halim Azizi ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Physical Properties ◽  
Chemical Reduction ◽  
Chemical Effect ◽  
Reduction Temperature ◽  
Reduction Behavior ◽  
Absorption Isotherm ◽  
Temperature Programmed ◽  
Bet Technique ◽  
Reduction Characteristics

The reduction behavior of nickel oxide (NiO) and zirconia (Zr) doped NiO (Zr/NiO) was investigated using temperature programmed reduction (TPR) using carbon monoxide (CO) as a reductant and then characterized using X-ray diffraction (XRD), nitrogen absorption isotherm using BET technique and FESEM-EDX. The reduction characteristics of NiO to Ni were examined up to temperature 700 °C and continued with isothermal reduction by 40 vol. % CO in nitrogen. The studies show that the TPR profile of doped NiO slightly shifts to a higher temperature as compared to the undoped NiO which begins at 387 °C and maximum at 461 °C. The interaction between ZrO2 with Ni leads to this slightly increase by 21 to 56 °C of the reduction temperature. Analysis using XRD confirmed, the increasing percentage of Zr from 5 to 15% speed up the reducibility of NiO to Ni at temperature 550 °C. At this temperature, undoped NiO and 5% Zr/NiO still show some crystallinity present of NiO, but 15% Zr/NiO shows no NiO in crystalline form. Based on the results of physical properties, the surface area for 5% Zr/NiO and 15% Zr/NiO was slightly increased from 6.6 to 16.7 m2/g compared to undoped NiO and for FESEM-EDX, the particles size also increased after doped with Zr on to NiO where 5% Zr/NiO particles were 110 ± 5 nm and 15% Zr/NiO 140 ± 2 nm. This confirmed that the addition of Zr to NiO has a remarkable chemical effect on complete reduction NiO to Ni at low reduction temperature (550 °C). This might be due to the formation of intermetallic between Zr/NiO which have new chemical and physical properties.

Influence of Zr Additive on the Chemical Reduction Behaviour of MoO3 in Carbon Monoxide Atmosphere

2021 ◽  
Vol 317 ◽  
pp. 173-179
Author(s):  
Alinda Samsuri ◽  
Mohd Nor Latif ◽  
Norliza Dzakaria ◽  
Fairous Salleh ◽  
Maratun Ajina Abu Tahari ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Molybdenum Trioxide ◽  
Chemical Reduction ◽  
Reduction Process ◽  
Chemical Effect ◽  
Physical Analysis ◽  
Tem Analysis ◽  
Transmission Electron ◽  
Reduction Behaviour ◽  
Temperature Programmed

Temperature-programmed reduction (TPR) was used to observe the chemical reduction behaviour of molybdenum trioxide (MoO3) and zirconia (Zr)-doped MoO3 catalyst by using carbon monoxide (CO) as the reductant. The characterisation of catalysts was performed by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) and transmission electron microscopy (TEM) analyses. The reduction performance were examined up to 700°C and reduction was continued for 60 min at 700°C in a stream of 20 vol. % CO in nitrogen. The TPR profile showed that the doped MoO­3 catalyst was slightly moved to a higher temperature (580°C) as compared to the undoped MoO3 catalyst, which began at around 550°C. The interaction between zirconia and molybdenum ions in doped MoO3 catalyst led to an increase in the reduction temperature. According to characterisation of the reduction products by using XRD, it revealed that the reduction behaviour of pure MoO3 to MoO2 by CO reductant involved two reduction stages with the formation of Mo4O11 as the intermediate product. Meanwhile, MoO3 catalyst doped with zirconia caused a delay in the reduction process and was proven by the presence of Mo4O11 species at the end of reactions. Physical analysis by using BET showed a slight increase in surface area of 3% Zr-MoO3 from 6.85 m2/g to 7.24 m2/g. As for TEM analysis, black tiny spots located around MoO3 particles revealed that the zirconia was successfully intercalated into MoO3 particles. This confirmed that formation of intermetallic between Zr-MoO3 catalyst will give new chemical and physical properties which has a remarkable chemical effect by disturbing the reduction progression of MoO3 catalyst.

Chemical Reduction Behaviour of NiO under Various Concentration of Carbon Monoxide Using TPR and XRD Techniques

2020 ◽  
Vol 1010 ◽  
pp. 379-384
Author(s):  
Salma Samidin ◽  
Maratun Najiha Abu Tahari ◽  
Siti Sarahah Sulhadi ◽  
Fairous Salleh ◽  
Norliza Dzakaria ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Chemical Reduction ◽  
Reduction Process ◽  
Reduction Behavior ◽  
Xrd Pattern ◽  
Nickel Carbide ◽  
Co Concentration ◽  
Reduction Behaviour ◽  
Mild Reduction ◽  
Xrd Techniques

The chemical reduction behavior of NiO under various carbon monoxide (CO) concentration as a reduction agent was studied. The NiO and Ni0 transformations were identified using TPR and XRD techniques. It was shown that, the completed reduction occurred at temperature 700 °C for 40% CO and 900 °C for 10% and 20% CO. During the chemical reduction process, nickel carbide was formed at temperature 400 °C and another formation of carbon amorphous appeared at 500 °C and proved through diffraction of XRD pattern at 2θ: 22.86 under 20% CO/N2 and and 2θ: 26.15 under 40% CO/N2. The interpretation of physisorption data showed that the pore size after reduction with various CO concentration comprised as microporous size in the range of 6-40 nm. Therefore, CO as a mild reduction agent stated that as the concentration of CO high, the rate of reduction affected and formed a very crystalline of Ni0 particle.

Reduction Behaviour of WO3 to W under Carbon Monoxide Atmosphere

2016 ◽  
Vol 840 ◽  
pp. 305-308
Author(s):  
Fairous Salleh ◽  
Tengku Shafazila Tengku Saharuddin ◽  
Alinda Samsuri ◽  
Rizafizah Othaman ◽  
Mohamed Wahab Mohamed Hisham ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Temperature Programmed Reduction ◽  
X Ray Diffraction ◽  
Reduction Behavior ◽  
X Ray ◽  
Isothermal Reduction ◽  
Reduction Behaviour ◽  
Temperature Programmed ◽  
Metal Phases

The reduction behaviour of tungsten oxide has been studied by using temperature programmed reduction (TPR) and X-ray diffraction (XRD). The reduction behavior were examine by nonisothermal reduction up to 900 oC then continued with isothermal reduction at 900 oC for 45 min time under (40% v/v) carbon monoxide in nitrogen (CO in N2) atmosphere. The TPR signal clearly shows one peak attributed to formation of suboxide W18O49 (more) and WO2 (less) observed at 80 min. The reduction product was investigated by varying the holding reaction time. Based on the characterization of the reduction products by using XRD, it was found that, nonisothermal reduction of WO3 at temperature 900 oC partially converted to some W18O49 and WO2 phases. However, after increased the reaction holding time for 45 min, WO3 phases disappeared and converted to WO2 and W metal phases. It is obviously shows that by hold the reduction time could improve the reducibility of the sample oxide. Furthermore, it is suggested that reduction by using CO as reducing agent follows the consecutives steps WO3 → WO2.92 → W18O49 → WO2 → W.

Effect of Noble Metal Silver on the Reduction Behaviour of Molybdenum Oxide Using Carbon Monoxide

2017 ◽  
Vol 888 ◽  
pp. 377-381
Author(s):  
Alinda Samsuri ◽  
Fairous Salleh ◽  
Tengku Shafazila Tengku Saharuddin ◽  
Rizafizah Othaman ◽  
Mohamed Wahab Mohamed Hisham ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Molybdenum Trioxide ◽  
Reduction Process ◽  
Reduction Peak ◽  
X Ray Diffraction ◽  
Reduction Behavior ◽  
X Ray ◽  
Reduction Behaviour ◽  
Temperature Programmed ◽  
Lower Temperature

The reduction behavior of silver doped molybdenum trioxide (Ag/MoO3) and undoped MoO3 by using carbon monoxide, CO were investigated by using temperature programmed reduction (TPR). The reduced phases were characterized by X-ray diffraction (XRD). In the carbon monoxide atmosphere, the XRD results indicated that the reduction of Ag/MoO3 and undoped MoO3 to MoO2 phase proceed in two steps (MoO3 → Mo4O11 → MoO2) with Mo4O11 present as an intermediate state. A complete reduction to metallic molybdenum for both samples cannot occurred since in an excess CO atmosphere, MoO2 is promoted to form carbides rather than reduce to metallic molybdenum. Nevertheless, addition of silver to modified MoO3 shows the better reducibility compared to MoO3 alone by lower the reducing temperature of MoO3. TPR results show that the reduction peak of Ag/MoO3 is slightly shifts to lower temperature as compared with the undoped MoO3. The interaction between silver and molybdenum ions leads to this slightly decrease of the reduction temperature of silver doped MoO3. It can be seen that doping with silver has a remarkable influence in the reduction process of the MoO3 catalyst.

Study on the Reduction Behavior of Molybdenum Oxide (MoO3) in Carbon Monoxide (CO) Atmosphere

2016 ◽  
Vol 840 ◽  
pp. 299-304 ◽  
Author(s):  
Alinda Samsuri ◽  
Tengku Shafazila Tengku Saharuddin ◽  
Fairous Salleh ◽  
Rizafizah Othaman ◽  
Mohamed Wahab Mohamed Hisham ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Molybdenum Trioxide ◽  
Xrd Analysis ◽  
Reduction Peak ◽  
X Ray Diffraction ◽  
Reduction Behavior ◽  
Isothermal Reduction ◽  
Intermediate Phases ◽  
Temperature Programmed ◽  
Isothermal Mode

The reduction behavior of molybdenum trioxide (MoO3) by carbon monoxide (CO) has been studied using temperature programmed reduction (TPR) and was characterized using X-ray diffraction spectroscopy (XRD). The TPR result shows that the first reduction peak of MoO3 under 20 vol. % CO in nitrogen started at 530 °C and second reduction peaks observed was at 700 °C. The XRD technique was employed to identify the changes in the sample. It was found that after non-isothermal reduction up to 700 °C, the intermediate phases Mo4O11 were observed. Completed reduction to MoO2 achieved after continued reduction with isothermal mode at 700 °C for 60 minutes. Based on the XRD analysis, it is confirmed that the reduction of MoO3 to MoO2 in CO atmosphere consists of two reduction stages, i) Mo6+ → Mo5+ and ii) Mo5+ → Mo4+. While, CO excess have resulted the formation of molybdenum carbide (Mo2C) rather than formation of metallic molybdenum (Mo).

Influence of Cerium Additive on the Reduction Behaviour of Tungsten Oxide under Carbon Monoxide Atmosphere

2017 ◽  
Vol 888 ◽  
pp. 389-393
Author(s):  
Fairous Salleh ◽  
Tengku Shafazila Tengku Saharuddin ◽  
Alinda Samsuri ◽  
Rizafizah Othaman ◽  
Mohammad Wahab Mohammad Hisham ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Reduction Peak ◽  
X Ray Diffraction ◽  
Reduction Behavior ◽  
Remarkable Effect ◽  
Isothermal Reduction ◽  
Temperature Programmed ◽  
Lower Temperature ◽  
Metal Phases

The reduction of pure WO3 and Ce/WO3 has been studied by using temperature programmed reduction (TPR), X-ray diffraction (XRD), and FESEM analysis. The reduction behavior were examined by non-isothermal reduction up to 900 oC then continued with isothermal reduction at 900 oC for 45 min under (40% v/v) carbon monoxide in nitrogen (CO in N2) atmosphere. The TPR results shows that reduction peak of Ce/WO3 were shifts to lower temperature as compared with to the pure WO3. In addition, TPR results indicate that addition with ceria give better reducibility compared to pure WO3. Based on the characterization of the reduction products after hold 45 min using XRD, pure WO3 were completely converted to WO2 and W metal phases. While, after addition of Ce to the WO3, the reduction was enhanced to W phases and some suboxide W5O14 and W3O5 with no WO2 phase remained and carbide observed. This is associated to the formation of alloy complex Ce2WO6 which gave remarkable effect to the reduction.

scholarly journals INFLUENCE OF CHROMIUM ON THE REDUCTION BEHAVIOR OF FERRIC OXIDE BY USING CARBON MONOXIDE: TEMPERATURE PROGRAMMED REDUCTION AND KINETIC STUDIES

2016 ◽  
Vol 20 (3) ◽  
pp. 531-538
Author(s):  
Tengku Shafazila Tengku Saharuddin ◽  
Alinda Samsuri ◽  
Fairous Salleh ◽  
Mohammad Bin Kassim ◽  
Rizafizah Othaman ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Ferric Oxide ◽  
Kinetic Studies ◽  
Temperature Programmed Reduction ◽  
Reduction Behavior ◽  
Temperature Programmed

ENPLATE NI-423

Alloy Digest ◽  
1986 ◽  
Vol 35 (11) ◽  
Keyword(s):  
Wear Resistance ◽  
Physical Properties ◽  
Surface Treatment ◽  
High Speed ◽  
Chemical Reduction ◽  
Electronic Devices ◽  
Electroless Nickel ◽  
Heat Treating ◽  
Corrosion And Wear ◽  
Phosphorus Alloy

Abstract ENPLATE NI-423 is a nickel-phosphorus alloy deposited by chemical reduction without electric current. It is deposited by a stable, relatively high-speed functional electroless nickel process that produces a low-stress coating with good ductility and excellent resistance to corrosion. Its many uses include equipment for chemicals and food, aerospace components, molds and electronic devices. This datasheet provides information on composition, physical properties, and hardness. It also includes information on corrosion and wear resistance as well as heat treating, machining, joining, and surface treatment. Filing Code: Ni-343. Producer or source: Enthone Inc..

Palladium Promoted Copolymerization of Carbon Monoxide with Polar or Nonpolar Olefinic Monomers

2020 ◽  
Vol 24 ◽  
Author(s):  
Yanlin Zong ◽  
Qiankun Li ◽  
Hongliang Mu ◽  
Zhongbao Jian
Keyword(s):  
Carbon Monoxide ◽  
Physical Properties ◽  
Vinyl Monomers ◽  
Pd Catalysts ◽  
Catalytic Systems

Abstract:: The copolymers of carbon monoxide (CO) and olefins, namely polyketones, are a family of widely used materi-als. In the catalytic preparation of these materials, palladium(II) catalysts represent the most successful catalytic systems. The production of both alternating and non-alternating polyketones has been achieved, with great difference in their physical properties. Herein, a variety of palladium(II) catalysts employed for the copolymerization of CO with various olefinic mon-omers such as ethylene, α-olefins, styrene and polar vinyl monomers are fully summarized. The influence of important fac-tors such as solvents and counterions on specific copolymerization, is also discussed. This review aims to enlighten the de-sign of new Pd catalysts with improved properties, as well as the development of new polyketone materials.

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