n-Heptane hydroconversion over sulfated-zirconia-supported molybdenum carbide catalysts

Abstract

Molybdenum carbide on sulfated zirconia was prepared by impregnation of MoO 3 on sulfated zirconia to give a loading of 5 wt% followed by carburisation at 923 K in a mixture of CH 4 /H 2 (4:1). The resulting catalyst was characterised by N 2 adsorption-desorption, CO chemisorption, FTIR of pyridine adsorption, XRD, TPR, TGA, Raman and SEM-EDX. This combination of characterisation studies suggests formation of a well-dispersed Mo 2 C phase over tetragonal zirconia. When employed in the hydroconversion of n-heptane, high temperature and low space velocity lead to substantial cracking. However, under some conditions, an increase in the research octane number (RON) from 0 (n-heptane) to ca. 50 was attained. Between 723 and 873 K, n-heptane is mainly cracked to iso-pentane and ethane. The product distribution as a function of conversion suggests that the reaction did not simply follow a consecutive reaction pathway, but that other parallel routes were involved.

Direct conversion of methane to C2 hydrocarbons using W supported on sulfated zirconia solid acid catalyst

“…SZ has distinct XRD pattern widely reported in the literature [24,32]. Different phases of SZ have been observed based on the synthesis technique and calcination temperatures [37,41].…”

“…The retentate was dried at 110 °C overnight followed by calcination at 550 °C for 4 h to prepare the final catalyst. W/SZ was synthesized by following the preparation method of Mo/SZ [24,32]. The catalyst was prepared using incipient wetness impregnation method with ammonium metatungstate hydrate as the precursor.…”

“…Although silica and alumina have been reported as strong non-reducible catalyst supports [30,31], recent studies have revealed zirconium oxides to demonstrate higher strength in working conditions [32]. It has been reported that the sulfurized form of ZrO 2 known as sulfated zirconia (SZ), actively helps the active metal sites to stabilize on the oxide support at a greater degree [29,33].…”

Molybdenum Carbide/Ni Nanoparticles Embedded into Carbon Nanofibers as an Effective Non-Precious Catalyst for Green Hydrogen Production from Methanol Electrooxidation

“…Molybdenum carbide stands out among the other transition metal carbides because of distinctive qualities and outstanding catalytic abilities in several reactions, such as the selective isomerization of hydrocarbons [18], hydrofining [19], water-gas shift [20], hydrodeoxygenation (HDO) of phenols [21], ammonia synthesis [22], hydrodesulfurization [23], hydrogen evolution reaction [24], and syngas to lower alcohols [25]. As an electrocatalyst, this compound showed a relatively good electrocatalytic performance for MOR and hydrogen electrooxidation reactions [26,27].…”

Influence of Reaction Temperature on the Interpretation of Delplots for the Parallel-Series Reaction Network

“…Hietala and Savage studied the kinetics of the hydrothermal reaction of cholesterol to cholestadienes and used the Delplot method to sort cholesta-2,4-diene, cholesta-3,5-diene, and cholesta-4,6-diene into a reaction network. The kinetics of catalytic cracking of n -heptane in the presence of molybdenum carbide catalysts supported on sulfated-zirconia were studied by Oloye et al The product classification and the reaction network were attained by applying the Delplot technique. It was found that the complicated reaction network included parallel and consecutive routes.…”