The Reduction Behaviour of Cerium Doped Iron Oxide in Hydrogen and Carbon Monoxide Atmosphere

2016 ◽  
Vol 840 ◽  
pp. 381-385
Author(s):  
Tengku Shafazila Tengku Saharuddin ◽  
Alinda Samsuri ◽  
Fairous Salleh ◽  
Rizafizah Othaman ◽  
Mohammad Kassim ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Iron Oxide ◽  
Metallic Iron ◽  
Reduction Process ◽  
Xrd Analysis ◽  
Temperature Programmed Reduction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reduction Behaviour ◽  
Temperature Programmed

The reduction behaviour of 3% cerium doped (Ce-Fe2O3) and undoped iron oxide (Fe2O3) by hydrogen in nitrogen (10%,v/v) and carbon monoxide in nitrogen (10%,v/v) atmospheres have been investigate by temperature programmed reduction (TPR). The phases formed of partially and completely reduced samples were characterized by X-ray diffraction spectroscopy (XRD). TPR results indicate that the reduction of Ce doped and undoped iron oxide in both reductants proceed in three steps reduction (Fe2O3 → Fe3O4 → FeO → Fe) with Fe3O4 and FeO were the intermediate. TPR results also suggested that by adding Ce metal into iron oxide the reduction to metallic Fe by using both reductant gaseous give better reducibility compare to the undoped Fe2O3. The reduction process of Ce and undoped Fe2O3 become faster when CO was used as a reductant instead of H2. Furthermore, in CO atmosphere, Ce-Fe2O3 give complete reduction to metallic iron at 700 0C which about 200 0C temperature lower than other samples. Meanwhile, XRD analysis indicated that Ce doped iron oxide composed better crystallite phases of Fe2O3 with higher intensity and a small amount of FeCe2O4.

scholarly journals Effect of Cobalt on Nickel Oxide Toward Reduction Behaviour in Hydrogen and Carbon Monoxide Atmosphere

2020 ◽  
Vol 1010 ◽  
pp. 373-378
Author(s):  
Norliza Dzakaria ◽  
Maratun Najiha Abu Tahari ◽  
Salma Samidin ◽  
Tengku Shafazila Tengku Saharuddin ◽  
Fairous Salleh ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Nickel Oxide ◽  
Reduction Process ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reduction Behaviour ◽  
One Step ◽  
Temperature Programmed ◽  
Co Doped

The reduction behaviour of cobalt doped with nickel oxide and undoped nickel oxide (NiO) by hydrogen (H2) in nitrogen (20%, v/v) and carbon monoxide (CO) in nitrogen (40%, v/v) atmospheres have been investigated by temperature programmed reduction (TPR). The phases formed of partially and completely reduced samples were characterized by X-ray diffraction spectroscopy (XRD). TPR results indicate that the reduction of Co doped and undoped nickel oxide in both reductants proceed in one step reduction (NiO → Ni) without intermediate. TPR results also suggested that by adding Co metal into NiO, the reduction to metallic Ni by both reductant gaseous give different intensity of the peak. The reduction process of Co and undoped NiO become faster when H2 was used as a reductant. Furthermore, in H2 atmosphere, Co-NiO give complete reduction to metallic Ni at 700 °C. Meanwhile, XRD analysis indicated that NiO without Co composed better crystallite phases of NiO with higher intensity.

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.

Au/iron oxide catalysts: temperature programmed reduction and X-ray diffraction characterization

1999 ◽  
Vol 329 (1) ◽  
pp. 39-46 ◽  
Author(s):  
G Neri ◽  
A.M Visco ◽  
S Galvagno ◽  
A Donato ◽  
M Panzalorto
Keyword(s):  
Iron Oxide ◽  
Oxide Catalysts ◽  
Temperature Programmed Reduction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Programmed

Studies of Fe Metal Carburization by Carbon Monoxide Using XRD and TPR Techniques

2017 ◽  
Vol 888 ◽  
pp. 524-528
Author(s):  
Norliza Dzakaria ◽  
Fairous Salleh ◽  
Tengku Shafazila Tengku Saharuddin ◽  
Alinda Samsuri ◽  
Azizul Hakim ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Free Energy ◽  
Carbon Content ◽  
Metallic Iron ◽  
Iron Carbide ◽  
Temperature Programmed Reduction ◽  
Amorphous Form ◽  
X Ray ◽  
Different Temperatures ◽  
Temperature Programmed

This study was undertaken to investigate the effect of carburization of metallic Fe by (20%,v/v) carbon monoxide (CO). Carburization of Fe by carbon monoxide was examined by using temperature-programmed reduction (TPR), X-Ray powder diffractometry (XRD) and Carbon Hydrogen Nitrogen Sulfur (CHNS) technique. Based on a thermodynamic calculation, the free energy Gibb’s value to produce carbon is-8.08 kcal/mol which are favorable. However, production of iron carbide from the same reaction, the free energy Gibb’s value is +9.24 kcal/mol which is not feasible. From the XRD results, shows that after carburization of Fe, the peak appears only for Fe but there is a broad peak between 20 – 30°. The peak might be indicated as carbon in amorphous form. This finding is supported by the percent of carbon content in CHNS analysis which are increasing when the temperature is increased. This shows that after carburization the carbon content is increasing with increasing in temperature due to carbon deposited on metallic iron. In this research, three different temperatures were used which are 300°C, 500°C and 700°C.

Temperature Programmed Reduction and X-Ray Diffraction Studies of Fe2O3 Reduction by Different Concentration of Carbon Monoxide

2015 ◽  
Vol 1087 ◽  
pp. 55-58
Author(s):  
Shafazila Tengku ◽  
Alinda Samsuri ◽  
Fairous Salleh ◽  
Rizafizah Othaman ◽  
Mohammad bin Kassim ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Iron Oxides ◽  
Carbide Phase ◽  
Iron Carbide ◽  
Temperature Programmed Reduction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Concentration ◽  
Temperature Programmed ◽  
Lower Temperature

Reduction of Fe2O3 by carbon monoxide (CO) have been studied by temperature programmed reduction (TPR) and X-ray diffraction spectroscopy (XRD). The influences of carbon monoxide concentration on the reducibility of iron oxides have been investigated. This study deals with the comparison in the reduction of Fe2O3 between 5% to 20% of CO concentration in the temperature range of 40–900 °C. The result shows that reducing behaviour of Fe2O3 is strongly dependent on the concentration of CO. It is suggested by using 20% of CO complete reduction takes place at lower temperature due to absence of intermediate FeO giving only two-steps reduction (Fe2O3 → Fe3O4 → metallic Fe). Moreover, excess of CO results the formation of iron carbide phase.

scholarly journals Influence of Cerium on the Reduction Behaviour of Iron Oxide by Using Carbon Monoxide: TPR and Kinetic Studies

2019 ◽  
Author(s):  
Tengku Shafazila Tengku Saharuddin ◽  
Nurul Syahira Ezzaty Nor Azman ◽  
Fairous Salleh ◽  
Alinda Samsuri ◽  
Rizafizah Othaman ◽  
...  
Keyword(s):  
Activation Energy ◽  
Carbon Monoxide ◽  
Iron Oxide ◽  
Reduction Process ◽  
Kinetic Studies ◽  
Xrd Analysis ◽  
Oxide Reduction ◽  
Iron Oxide Reduction ◽  
Reduction Behaviour ◽  
Lower Temperature

Reduction of iron oxide is one of the most studied topics owing to the importance of iron/steel industry and also has been used as a precursor and active component in a number of important chemical processes. The interaction between iron oxide and other metal additive have gained interest in the past two decades due to the ability on enhancing the reduction performance of the iron oxide. Therefore, this study was undertaken to investigate the influence of cerium on the reduction behaviours of iron oxide by (10%, v/v) carbon monoxide in nitrogen. The cerium doped (Ce-Fe2O3) and non-doped iron oxide reduction behaviour and the kinetic studies have been studied by temperature programmed reduction (TPR) and the phases formed of partially and completely reduced samples were characterized by X-ray diffraction spectroscopy (XRD) while the activation energy values were calculated from Arrhenius equation using Wimmer’s method. TPR results indicate that the reduction of doped and undoped iron oxide proceeds in three steps reduction (Fe2O3 ? Fe3O4 ? FeO ? Fe), while doped iron oxide showed a large shifted towards lower temperature especially in the transition steps of FeO ? Fe. Furthermore, TPR results also suggested that by adding Ce metal into iron oxide the reduction of metal iron completed at lower temperature (700 ?C) compared to non-doped iron oxide (900 ?C). Meanwhile, XRD analysis indicated that doped iron oxide composed of Fe2O3 and a small amount of FeCe2O4. The increase in the rates of iron oxide reduction may relate to the presence of cerium species in the formed of FeCe2O4 and was confirmed by the decrease in the activation energy regarding to all transition phases (Fe2O3 ? Fe3O4 ? FeO ? Fe) during the reduction process

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.

Reduction of Molybdenum Trioxide by Using Hydrogen

2017 ◽  
Vol 888 ◽  
pp. 404-408 ◽  
Author(s):  
Mohd Nor Latif ◽  
Alinda Samsuri ◽  
Mohamed Wahab Mohamed Hisham ◽  
Mohd Ambar Yarmo
Keyword(s):  
Molybdenum Trioxide ◽  
Reduction Step ◽  
Temperature Programmed Reduction ◽  
X Ray Diffraction ◽  
Thermodynamic Consideration ◽  
Rapid Reduction ◽  
Reduction Behavior ◽  
X Ray ◽  
Intermediate Phases ◽  
Temperature Programmed

Metallic molybdenum was synthesized through reduction of molybdenum trioxide (MoO3) by using hydrogen as a reducing agent. The reduction behavior of MoO3 were investigated by using temperature programmed reduction (TPR). The reduced phases were characterized by X-ray diffraction spectroscopy (XRD). The XRD results indicate that the reduction of MoO3 proceed in two steps reduction (MoO3 → MoO2 → Mo) with formation of intermediate phases of Mo4O11 during first step of reduction. However, the TPR results showed only one broad peak that correspond to all reduction step that was merge into one peak. It seem that, increasing the temperature cause the rapid reduction that correlated with thermodynamic consideration data that show the formation of metallic molybdenum is become feasible by increasing the temperature.

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