Hong, Seung Tae Park, Dal Ryung Yoo, Seung-Joon Kim, Jae-Duck Park, Hyung Sang 2024-01-21T02:01:28Z 2024-01-21T02:01:28Z 2021-09-02 2006-12 0922-6168 https://pubs.kist.re.kr/handle/201004/134870 The active phase of the NiMo/Al2O3 catalyst for hydrodesulfurization reactions has been investigated in this work. Special attention has been focused on the effect of the order of metal impregnation on the formation of the active phase in the reaction. The Mo and Ni oxides and their sulfides on the alumina were investigated by XPS and DRS analyses. The Ni-Mo oxides or precursor of the active phase which are chemically bonded between Mo and Ni were also confirmed from the binding energy shifts of the XPS peaks. The amount of Ni-Mo oxides was determined after the formation of metal oxides during calcination. The Ni-Mo sulfide (active phase) was then induced through sulfidation. It was important that Mo should be located at the tetrahedral sites on the alumina with a high Mo dispersion. These results indicated that there are two important factors in preparing highly efficient Ni-Mo catalysts; one is that Mo should be located at the tetrahedral coordination on Al2O3 in high dispersion (Mo/Al2O3) and the other is that the Ni species should be supported on MoAl2O4 to form Ni-Mo oxides which change into the Ni-Mo sulfide active sites by sulfidation. English VSP BV MOSSBAUER EMISSION-SPECTROSCOPY MOLYBDENA-ALUMINA CATALYSTS TEMPERATURE-PROGRAMMED REDUCTION CO-MO CATALYSTS SUPPORTED CO NO ADSORPTION S PHASE SURFACE HYDROGENATION REDUCIBILITY Characterization of the active phase of NiMo/Al2O3 hydrodesulfurization catalysts Article 10.1163/156856706778938473 1 RESEARCH ON CHEMICAL INTERMEDIATES, v.32, no.9, pp.857 - 870 RESEARCH ON CHEMICAL INTERMEDIATES 32 9 857 870 scie scopus 000243596100006 2-s2.0-33846263102 Chemistry, Multidisciplinary Chemistry Review MOSSBAUER EMISSION-SPECTROSCOPY MOLYBDENA-ALUMINA CATALYSTS TEMPERATURE-PROGRAMMED REDUCTION CO-MO CATALYSTS SUPPORTED CO NO ADSORPTION S PHASE SURFACE HYDROGENATION REDUCIBILITY hydrodesulfurization active phase binding energy shift XPS DRS tetrahedral Mo NiO impregnation order