Mn-MCM-41 was synthesized by the hydrothermal method. The synthesized material was characterized by various physicochemical techniques such as small angle X-ray diffraction, elemental analysis, Fourier transform infrared spectroscopy and diffuse reflectance ultraviolet-visible spectroscopy. The gas-phase cyclohexanol and air reaction over Mn-MCM-41 molecular sieve was studied for the first time. The conversion is almost constant even up to 5 h, and follows a parabolic behavior with respect to temperature. The conversion reaches a maximum at 350°C and selectivity towards cyclohexene is increased with temperature. The conversion and cyclohexene selectivity were increased with flow rate.
The influence of order of the impregnation of NiO and MoO3 on the structure and catalytic behavior of H-AlMCM-41 supported Ni−Mo catalysts for hydrodenitrogenation (HDN) has been investigated. These catalysts were well characterized by TEM, XRD, N2 adsorption−desorption, XPS, and FT-IR spectra of CO adsorption and tested for hydrodenitrogenation (HDN) of o-toluidine and cyclohexylamine. It was found that the catalyst prepared by sequential impregnation of NiO and MoO3 was more active than the catalyst prepared by coimpregnation. Among the sequentially impregnated catalysts, the catalyst in which NiO deposited first followed by MoO3 shows high HDN activity. TEM, FT-IR spectra of CO adsorption, and estimation of total sulfur of sulfide catalyst results clearly show that the NiO and MoO3 are well dispersed over H-AlMCM-41 on reverse order impregnated catalyst. The very low activity of coimpregnated catalyst is attributed to poor dispersion of metal oxides as well as due to the formation of stable stoichiometric oxide and aggregates of metal particle over the support surface.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.