CO2 Reforming of Methane to Produce Syngas over γ-Al2O3-Supported Ni–Sr Catalysts

Abstract

Dry reforming reactions have important environmental implications, since they can utilize and/or mitigate greenhouse gases. An experimental study was carried out to prepare suitable catalysts for dry reforming of methane. The Ni/γ-Al2O3 supported catalysts with strontium as a promoter (0.00–2.25 wt %) were prepared by a wet impregnation method. Various experimental techniques such as N2 adsorption–desorption isotherm, H2-TPR, CO2-TPD, XRD, TGA, O2-TPO, and SEM were applied for characterization of fresh and spent catalysts. The results of characterizations and catalyst activity test revealed that addition of Sr in Ni/γ-Al2O3 catalyst has dual effect; it improves the metal support interaction as well as enhances the Lewis basicity of the catalyst. This boost in basicity favors the chemisorption and dissociation of CO2 over the catalyst which in turn decreases the coke deposition. Amongst all tested catalysts, best results in terms of coke suppression were attained when 0.75% Sr loading was used, which showed 3.8% weight loss, less than half of that of the parent Ni–Al catalyst (8.2 wt %).

Effects of Platinum and Palladium Metals on Ni/Mg1-xZrxO Catalysts in the CO2 Reforming of Methane

“…In the case of a high ZrO2 concentration, the conversion rate for both CH4 and CO2 declined. The decrease could be attributed to the higher electron density of Pt, Pd, and Ni [38]. The decomposition of the ZrOCO3 species in DRM has produced CO and an oxygen species that react with the carbon deposits on the interface of Pt, Pd, and Ni-ZrOCO3 thus reviving the activity sites of the Pt, Pd, and Ni.…”

“…Figure 11 presents data that show improvement in the conversion of CH4 from 91 to 96 %. This improvement is achieved by adding an oxidant (O2) to partially or completely oxidize methane together with the use of exothermicity in the reaction that supplies the necessary direct heat to the DRM reactant mixture [38]. However, this process does not affect the CO2 conversion and the H2/CO ratio because of the reaction between oxygen and CH4 to produce CO and H2O (Equation 22).…”

Low temperature dry methane reforming over Ce, Zr and CeZr promoted Ni–Mg–Al hydrotalcite-derived catalysts

“…Dry methane reforming (DMR) has attracted considerable attention in the last decades as a perspective method for CO 2 valorization, yielding an equimolar mixture of H 2 and CO. Such a syngas can be directly used for liquid fuel synthesis through the Fischer-Tropsch process, or for the production of valuable oxygenated compounds [1,2]. However, the DMR process presents still important drawbacks towards its practical application, mainly related to the simultaneous occurrence of carbon-forming reactions, such as direct methane decomposition, and, to a lesser extent, the Boudouard reaction [3][4][5].…”

Ni-containing Ce-promoted hydrotalcite derived materials as catalysts for methane reforming with carbon dioxide at low temperature – On the effect of basicity

“…Dry reforming of methane (DRM) has been considered during the past few decades as a prospective process for the valorization of carbon dioxide, yielding a syngas with equimolar H 2 /CO ratio, suitable for its direct use in different chemical reactions, such as Fischer-Tropsch synthesis, or for the production of oxygenated compounds [9][10][11][12]. The main issue about DRM is the fast deactivation of the catalyst, due to the formation of coke deposits and to the sintering of the active phase [13][14][15].…”