Amir Mosayebi, Atieh Ranjbar, Mohammad Hosein Eghbal Ahmadi
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引用次数: 0
Abstract
In current work, the investigation centered on assessing the impact of the CeO2 to Al2O3 ratio in a 5%Ni/CeO2–Al2O3 catalyst on the CO2 hydrogenation reaction within the temperature range of 240–400 °C. The primary aim was to achieve enhanced conversion rates, while minimizing coke deposition on the catalyst surface. Nickel was incorporated into the CeO2–Al2O3 supports via the deposition–precipitation method. The various physicochemical properties of fresh, reduced and spent catalysts were studied using techniques such as thermal gravimetric analysis (TGA), X-ray diffraction (XRD), N2 adsorption/desorption, temperature programmed reduction (TPR), H2-chemisorption, X-ray fluorescence (XRF), and CHNS analyzer. XRD results revealed that the addition of CeO2 to the Ni/Al2O3 catalyst and the increase in ceria loading in the hybrid support had no obvious effect on the crystalline structure. However, several properties including reducibility, coke deposition, and coke formation quantity, coke structure on the catalyst surface, catalytic performance, and thermal stability were altered. The CO2 conversion remained relatively stable (41.25%) up to 35 h initial on stream for Ni/Al2O3 catalyst, indicating no significant deactivation. Conversely, Ni/CeO2–Al2O3 catalyst exhibited high stability up to 45 h initial. The highest CO2 conversion (58%) was achieved with the Ni/CeO2 (50%)–Al2O3 (50%) at 400 °C, primarily attributed to a lower interaction between nickel species and the support, along with a higher reduction degree. Ni/CeO2–Al2O3 catalysts displayed higher methane selectivity and lower CO selectivity compared to both Ni/Al2O3 and Ni/CeO2 catalysts across the entire temperature range of 240–400 °C.
期刊介绍:
Research on Chemical Intermediates publishes current research articles and concise dynamic reviews on the properties, structures and reactivities of intermediate species in all the various domains of chemistry.
The journal also contains articles in related disciplines such as spectroscopy, molecular biology and biochemistry, atmospheric and environmental sciences, catalysis, photochemistry and photophysics. In addition, special issues dedicated to specific topics in the field are regularly published.