On the Synthesis of Molybdenum Carbide With Cobalt Addition via Gas-Solid Reactions in a Ch4/H2 Atmosphere

Abstract

-Due to ever more severe environmental regulations regarding SOx, NOx and other pollutants' emissions, there has been an interest in developing new and improved catalysts for hydroprocessing reactions. Mo2C has been reported to display good selectivity and activity for those reactions, especially for HDS. Addition of another metal to the carbide structure may improve catalytic properties. Mo2C with low cobalt addition (2.5 and 5%) was obtained via gas-solid reaction in a fixed bed reactor with CH4 (5%)/H2 atmosphere. XRD and TG/DTA analysis of the precursors were carried out in order to understand its mass loss profile, doping metal presence and phase distributions. CoMoO4 as well as MoO3 were identified after calcining doped precursors at 600 °C/180min. SEM, XRD, XRF, TOC, BET and laser granulometric analysis of the reaction products were also performed. Compositions verified by XRF and theoretical values were compatible. At 700 °C both carbide (Mo2C) and oxide (MoO2) phases are present, as identified in XRD analysis and observed by SEM. At 750 °C only single phase Mo2C was verified by XRD, indicating Co dispersion on the carbide matrix. Morphology at this temperature is compatible with pure Mo2C, though XRF indicates Co presence on the material.

Effects of reaction parameters on the deoxygenation of soybean oil for the sustainable production of hydrocarbons

“…The catalyst was then carburized with a process shown in previous literature. 33,34 The catalyst was carburized on a stainless steel reactor with a capacity for 10 g of catalyst. During the carburization, a flow of 250 ml/min of a mixture containing 20% CH 4 in H 2 was passed through the reactor.…”

Improved Brønsted to Lewis (B/L) Ratio of Co- and Mo-Impregnated ZSM-5 Catalysts for Palm Oil Conversion to Hydrocarbon-Rich Biofuels

“…Wang et al [17] reported that the highest diffraction peak of α-MoO3 appears at 2θ = 27.36°; meanwhile, Sen et al [18] reported that it appears at 2θ = 27.32°. Moreover, new peaks appear at 2θ = 26.5, 27.3, 28.2, 32.2, and 33.8° in the Co-Mo/ZSM-5 catalyst, corresponding to β-CoMoO4 (JCPDS-21-0868) [20][21][22][23]. Based on this analysis, it can be deduced that the metals have been impregnated with the ZSM-5 catalyst due to the appearance of the peaks corresponding to the impregnated metals.…”

“…On the other hand, the peak at 2θ = 27.6 • in ZSM-5 is sharpened/heightened and shifted to 27.4 • due to the presence of the highest corresponding peak of α-MoO 3 . Wang et al [17] reported that the highest diffraction peak of α-MoO 3 appears at 2θ = 27.36 • ; meanwhile, Sen et al [18] reported that it appears at 2θ = 27.32 [20][21][22][23]. Based on this analysis, it can be deduced that the metals have been impregnated with the ZSM-5 catalyst due to the appearance of the peaks corresponding to the impregnated metals.…”

Liquid-Phase Hydrodeoxygenation of Guaiacol over Mo2C Supported on Commercial CNF. Effects of Operating Conditions on Conversion and Product Selectivity

“…Mo 2 C/CNF catalyst also showed a major reflexion intensity at 26 • and a minor peak at 45 • , with both being assigned to the graphitic carbon phase. The same diffractograms also revealed seven small peaks assigned to the molybdenum carbide phase (Mo 2 C), with reflexions detected at 2θ angles of 34 • , 38 • , 40 • , 52 • , 61 • , 69 • , 75 • , and 76 • , assigned to orthorhombic Mo 2 C (lattice parameters a = 0.4724 nm, b = 0.6002 nm, c = 0.5215 nm) [11,[29][30][31][32][33]. The size of the crystallites (interpreted here as coherent diffraction domains) estimated by XRD is ca.…”