SOFIU MAHMUD

Mr. SOFIU MAHMUD

King Saud University, Saudi Ar

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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25 April 2020 in Processes
Verified
Journal Article
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Anis H. FakeehaAnis H. Fakeeha
Anis H. Fakeeha
AIAhmed Aidid Ibrahim
Ahmed Aidid Ibrahim
HAHesham Aljuraywi
Hesham Aljuraywi
YAYazeed Alqahtani
Yazeed Alqahtani
AAAhmad Alkhodair
Ahmad Alkhodair
Ahmed S Al-FateshAhmed S Al-Fatesh
Ahmed S Al-Fatesh
The catalytic activity of the partial oxidation reforming reaction for hydrogen production over 10% Ni supported on high and low surface area alumina and zirconia was investigated. The reforming reactions, under atmospheric pressure, were performed with a feed molar ratio of CH4/O2 = 2.0. The reaction temperature was set to 450–650 °C. The catalytic activity, stability, and carbon formation were determined via TGA, TPO, Raman, and H2 yield. The catalysts were calcined at 600 and 800 °C. The catalysts were prepared via the wet-impregnation method. Various characterizations were conducted using BET, XRD, TPR, TGA, TPD, TPO, and Raman. The highest methane conversion (90%) and hydrogen yield (72%) were obtained at a 650 °C reaction temperature using Ni-Al-H-600, which also showed the highest stability for the ranges of the reaction temperatures investigated. Indeed, the time-on-stream for 7 h of the Ni-Al-H-600 catalyst displayed high activity and a stable profile when the reaction temperature was set to 650 °C.

23 March 2022 in Catalysts
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Journal Article
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AIAhmed Aidid Ibrahim
Ahmed Aidid Ibrahim
Anis H. FakeehaAnis H. Fakeeha
Anis H. Fakeeha
SOFIU MAHMUDSOFIU MAHMUD
SOFIU MAHMUD
AAAbdulrhman Alawadi
Abdulrhman Alawadi
SASalwa Alreshaidan
Salwa Alreshaidan
Ahmed S Al-FateshAhmed S Al-Fatesh
Ahmed S Al-Fatesh
Dry reforming of methane (DRM) over an Ni-based catalyst is an innovative research area due to the growing environmental awareness about mitigating global warming gases (CH4 and CO2) and creating a greener route of synthesis. Herein, 5% Ni supported on ZrO2 obtained from various sources was prepared by the impregnation method. The catalysts were calcined at 600, 700, and 800 °C. Furthermore, Ni-RC stabilized with MgO, SiO2, TiO2, and Y2O3 were tested. Characterization techniques employed comprise the N2 physisorption, infrared spectroscopy, Raman, thermogravimetric analysis, XRD, and TEM. The results of the present study indicated that the ZrO2 support source had a profound effect on the overall performance of the process. The best catalyst Ni-RC gave an average conversion of CH4 and CO2 of 61.5% and 63.6% and the least deactivation of 10.3%. The calcination pretreatment differently influenced the catalyst performance. When the average methane conversion was higher than 40%, increasing the calcination temperature decreased the activity. While for the low activity catalysts with an average methane conversion of less than 40% the impact of the calcination temperature did not constantly decrease with the temperature rise. The stabilization of Ni-RC denoted the preference Y2O3 stabilized catalyst with average values of CH4 and CO2 conversion of about 67% and 72%, respectively. The thorough study and fine correlation will be advantageous for technologically suitable Ni-15Y-RC catalysts for DRM.

28 April 2020 in Processes
Verified
Journal Article
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Anis H. FakeehaAnis H. Fakeeha
Anis H. Fakeeha
ABAbdulaziz Bagabas
Abdulaziz Bagabas
SOFIU MAHMUDSOFIU MAHMUD
SOFIU MAHMUD
Ahmed OsmanAhmed Osman
Ahmed Osman
SKSamsudeen Kasim
Samsudeen Kasim
Ahmed S Al-FateshAhmed S Al-Fatesh
Ahmed S Al-Fatesh
Dry reforming of CH4 was conducted over promoted Ni catalysts, supported on mesoporous gamma-alumina. The Ni catalysts were promoted by various metal oxides (CuO, ZnO, Ga2O3, or Gd2O3) and were synthesized by the incipient wetness impregnation method. The influence of the promoters on the catalyst stability, coke deposition, and H2/CO mole ratio was investigated. Stability tests were carried out for 460 min. The H2 yield was 87% over 5Ni+1Gd/Al, while the CH4 and CO2 conversions were found to decrease in the following order: 5Ni+1Gd/Al > 5Ni+1Ga/Al > 5Ni+1Zn/Al > 5Ni/Al > 5Ni+1Cu/Al. The high catalytic performance of 5Ni+1Gd/Al, 5Ni+1Ga/Al, and 5Ni+1Zn/Al was found to be closely related to their contents of NiO species, which interacted moderately and strongly with the support, whereas free NiO in 5Ni+1Cu/Al made it catalytically inactive, even than 5Ni/Al. The 5Ni+1Gd/Al catalyst showed the highest CH4 conversion of 83% with H2/CO mole ratio of ~1.0.

20 November 2020 in Processes
Verified
Journal Article
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SOFIU MAHMUDSOFIU MAHMUD
SOFIU MAHMUD
Ahmed S Al-FateshAhmed S Al-Fatesh
Ahmed S Al-Fatesh
Anis H. FakeehaAnis H. Fakeeha
Anis H. Fakeeha
SKSamsudeen Kasim
Samsudeen Kasim
AIAhmed Aidid Ibrahim
Ahmed Aidid Ibrahim
AAAhmed E Abasaeed
Ahmed E Abasaeed
Nickel catalysts supported on zirconium oxide and modified by various amounts of lanthanum with 10, 15, and 20 wt.% were synthesized for CO2 reforming of methane. The effect of La2O3 as a promoter on the stability of the catalyst, the amount of carbon formed, and the ratio of H2 to CO were investigated. In this study, we observed that promoting the catalyst with La2O3 enhanced catalyst activities. The conversions of the feed, i.e., methane and carbon dioxide, were in the order 10La2O3 > 15La2O3 > 20La2O3 > 0La2O3, with the highest conversions being about 60% and 70% for both CH4 and CO2 respectively. Brunauer–Emmett–Teller (BET) analysis showed that the surface area of the catalysts decreased slightly with increasing La2O3 doping. We observed that 10% La2O3 doping had the highest specific surface area (21.6 m2/g) and the least for the un-promoted sample. The higher surface areas of the promoted samples relative to the reference catalyst is an indication of the concentration of the metals at the mouths of the pores of the support. XRD analysis identified the different phases available, which ranged from NiO species to the monoclinic and tetragonal phases of ZrO2. Temperature programmed reduction (TPR) analysis showed that the addition of La2O3 lowered the activation temperature needed for the promoted catalysts. The structural changes in the morphology of the fresh catalyst were revealed by microscopic analysis. The elemental compositions of the catalyst, synthesized through energy dispersive X-ray analysis, were virtually the same as the calculated amount used for the synthesis. The thermogravimetric analysis (TGA) of spent catalysts showed that the La2O3 loading of 10 wt.% contributed to the gasification of carbon deposits and hence gave about 1% weight-loss after a reaction time of 7.5 h at 700 °C.

23 April 2021 in Energies
Verified
Journal Article
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AAAhmed E Abasaeed
Ahmed E Abasaeed
SKSamsudeen Kasim
Samsudeen Kasim
WKWasim Ullah Khan
Wasim Ullah Khan
SOFIU MAHMUDSOFIU MAHMUD
SOFIU MAHMUD
AIAhmed Aidid Ibrahim
Ahmed Aidid Ibrahim
Ahmed S Al-FateshAhmed S Al-Fatesh
Ahmed S Al-Fatesh
Development of a transition metal based catalyst aiming at concomitant high activity and stability attributed to distinguished catalytic characteristics is considered as the bottleneck for dry reforming of methane (DRM). This work highlights the role of modifying zirconia (ZrO2) and alumina (Al2O3) supported nickel based catalysts using lanthanum oxide (La2O3) varying from 0 to 20 wt% during dry reforming of methane. The mesoporous catalysts with improved BET surface areas, improved dispersion, relatively lower reduction temperatures and enhanced surface basicity are identified after La2O3 doping. These factors have influenced the catalytic activity and higher hydrogen yields are found for La2O3 modified catalysts as compared to base catalysts (5 wt% Ni-ZrO2 and 5 wt% Ni-Al2O3). Post-reaction characterizations such as TGA have showed less coke formation over La2O3 modified samples. Raman spectra indicates decreased graphitization for La2O3 catalysts. The 5Ni-10La2O3-ZrO2 catalyst produced 80% hydrogen yields, 25% more than that of 5Ni-ZrO2. 5Ni-15La2O3-Al2O3 gave 84% hydrogen yields, 8% higher than that of 5Ni-Al2O3. Higher CO2 activity improved the surface carbon oxidation rate. From the study, the extent of La2O3 loading is dependent on the type of oxide support.

16 May 2022 in Materials
Verified
Journal Article
Open access
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SOFIU MAHMUDSOFIU MAHMUD
SOFIU MAHMUD
AAAhmed E Abasaeed
Ahmed E Abasaeed
Anis H. FakeehaAnis H. Fakeeha
Anis H. Fakeeha
AIAhmed Aidid Ibrahim
Ahmed Aidid Ibrahim
AAAbdullah A. Alquraini
Abdullah A. Alquraini
Ahmed S Al-FateshAhmed S Al-Fatesh
Ahmed S Al-Fatesh
Methane Dry Reforming is one of the means of producing syngas. CeNi0.9Zr0.1O3 catalyst and its modification with yttrium were investigated for CO2 reforming of methane. The experiment was performed at 800 °C to examine the effect of yttrium loading on catalyst activity, stability, and H2/CO ratio. The catalyst activity increased with an increase in yttrium loading with CeNi0.9Zr0.01Y0.09O3 catalyst demonstrating the best activity with CH4 conversion >85% and CO2 conversion >90% while the stability increased with increases in zirconium loading. The specific surface area of samples ranged from 1–9 m2/g with a pore size of 12–29 nm. The samples all showed type IV isotherms. The XRD peaks confirmed the formation of a monoclinic phase of zirconium and the well-crystallized structure of the perovskite catalyst. The Temperature Program Reduction analysis (TPR) showed a peak at low-temperature region for the yttrium doped catalyst while the un-modified perovskite catalyst (CeNi0.9Zr0.1O3) showed a slight shift to a moderate temperature region in the TPR profile. The Thermogravimetric analysis (TGA) curve showed a weight loss step in the range of 500–700 °C, with CeNi0.9Zr0.1O3 having the least carbon with a weight loss of 20%.