Impact of Ce-Loading on Ni-catalyst supported over La2O3+ZrO2 in methane reforming with CO2. (27th November 2020)

• Record Type: Journal Article
• Authors: Kasim, Samsudeen Olajide; Al-Fatesh, Ahmed Sadeq; Ibrahim, Ahmed Aidid; Kumar, Rawesh; Abasaeed, Ahmed Elhag; Fakeeha, Anis Hamza
• Is Part Of: International journal of hydrogen energy. Volume 45:Number 58(2020)
• Page Start: 33343
• Page End: 33351
• Publication Date: 2020-11-27
• Subjects: Lanthanum-Zirconia support -- Nickel doped -- Ceria promoter -- Basic sites -- Reducible NiO; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2020.08.289
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: This paper investigated the effect of doping Ni supported catalysts with different ceria loading. The catalysts (5%Ni+x%Ce/La2 O3 +ZrO2, where x = 0, 1, 2, 2.5, 3, 5) were synthesized via the wet impregnation technique and tested for methane reforming with carbon dioxide at atmospheric pressure, 700 °C and 42, 000 ml/gcat .h gas hourly space velocity. The fresh catalysts were subjected to different characterization techniques such as X-ray diffraction, Surface area and pore analysis, H2 -temperature programmed reduction, CO2 -temperature programmed desorption and thermogravimetric analysis (TGA). A fine correlation between characterization results and catalytic activity is found. The results of the reactions indicated that 5%Ni/La2 O3 +ZrO2 has the lowest conversion which increased with the percentage loading of CeO2 up to 2.5 wt % and then began to decline. This suggests that 2.5 wt % loading is the optimum for CH4 and CO2 conversion. This particular catalyst composition has NiO species that could be reduced easily, as well as dense and wide distribution of all type of basic sites with respect to other catalyst system. The used catalysts were again subjected to TGA and RAMAN analysis where the least carbon deposition and the least deactivation factor was observed for 5%Ni+5%Ce/La2 O3 +ZrO2 catalysts. Highlights: Ceria promoted showed better catalytic activity and stability for more than 7 h. Oxygen storage capacity, rapid and repeatable reduction-oxidation cycle are vital. Sufficient and strong basic sites enhance CO2 adsorption and promotes dry reforming. Ce modified catalyst has improved graphitization and less carbon deposits. Ceria loading of 2.5 wt % was the optimum loading.