H₂ production through dry reforming of methane (DRM) is a hot topic amidst growing environmental and atom-economy concerns. Loading Ni-based reducible mixed oxide systems onto a thermally stable support is a reliable approach for obtaining catalysts of good dispersion and high stability. Herein, NiO was dispersed over MO_x-modified-γ-Al₂O₃ (M = Ti, Mo, Si, or W; x = 2 or 3) through incipient wetness impregnation followed by calcination. The obtained catalyst systems were characterized by infrared, ultraviolet–visible, and X-ray photoelectron spectroscopies, and H₂ temperature-programmed reduction. The mentioned synthetic procedure afforded the proper nucleation of different NiO-containing mixed oxides and/or interacting-NiO species. With different modifiers, the interaction of NiO with the γ-Al₂O₃ support was found to change, the Ni²⁺ environment was reformed exclusively, and the tendency of NiO species to undergo reduction was modified greatly. Catalyst systems 5Ni3MAl (M = Si, W) comprised a variety of species, whereby NiO interacted with the modifier and the support (e.g., NiSiO₃, NiAl₂O₄, and NiWO₃). These two catalyst systems displayed equal efficiency, >70% H₂ yield at 800 °C, and were thermally stable for up to 420 min on stream. 5Ni3SiAl catalyst regained nearly all its activity during regeneration for up to two cycles.

Dry reforming of methane (DRM) over an Ni-based catalyst is an innovative research area due to the growing environmental awareness about mitigating global warming gases (CH₄ and CO₂) and creating a greener route of synthesis. Herein, 5% Ni supported on ZrO₂ obtained from various sources was prepared by the impregnation method. The catalysts were calcined at 600, 700, and 800 °C. Furthermore, Ni-RC stabilized with MgO, SiO₂, TiO₂, and Y₂O₃ were tested. Characterization techniques employed comprise the N₂ physisorption, infrared spectroscopy, Raman, thermogravimetric analysis, XRD, and TEM. The results of the present study indicated that the ZrO₂ support source had a profound effect on the overall performance of the process. The best catalyst Ni-RC gave an average conversion of CH₄ and CO₂ of 61.5% and 63.6% and the least deactivation of 10.3%. The calcination pretreatment differently influenced the catalyst performance. When the average methane conversion was higher than 40%, increasing the calcination temperature decreased the activity. While for the low activity catalysts with an average methane conversion of less than 40% the impact of the calcination temperature did not constantly decrease with the temperature rise. The stabilization of Ni-RC denoted the preference Y₂O₃ stabilized catalyst with average values of CH₄ and CO₂ conversion of about 67% and 72%, respectively. The thorough study and fine correlation will be advantageous for technologically suitable Ni-15Y-RC catalysts for DRM.

Dry reforming of methane (DRM) has important and positive environmental and industrial impacts, as it consumes two of the top greenhouse gases in order to produce syngas (H₂ and CO) and thus hydrogen (H₂). The performance of DRM of conversions of CH₄ and CO₂ was investigated over Ni/ZrO₂ catalysts. The catalytic performance of all prepared catalysts for DRM was assessed in a micro-tubular fixed bed reactor under similar reaction conditions (i.e., activation and reaction temperatures at 700 °C, a feed flow rate of 70 mL/min, reaction temperature, and a 440 min reaction time). Various characterization techniques, such as BET, CO₂-TPD, TGA, XRD, EDX, and TEM, were employed. The zirconia support was modified with MgO or Y₂O₃. The yttria-stabilized zirconia catalyst (5Ni15YZr) provided the optimum activity performance of CH₄ and CO₂ conversions of 56.1 and 64.3%, respectively, at 700 °C and a 70 mL/min flow rate; this catalyst also had the highest basicity. The Ni-based catalyst was promoted with Cs, Ga, and Sr. The Sr-promoted catalyst produced the highest enhancement of activity. The influence of the reaction temperature and the feed flow rate on 5Ni15YZr and 5NiSr15YZr indicated that the activity increased with the increase in the reaction temperature and lower feed flow rate. For 5Ni3Sr15YZr, at a reaction temperature of 800 °C, the CH₄ and CO₂ conversions were 76.3 and 79.9%, respectively, whereas at 700 °C, the conversions of CH₄ and CO₂ were 66.6 and 79.6% respectively.

Carbon dioxide reforming of methane (CRM) converts CH₄ and CO₂ greenhouse gases into syngas over nickel-based catalysts. We performed CRM in a tubular microreactor at 700 °C by using 5.0 wt.% NiO catalyst, supported over mixtures of γ-Al₂O₃ + x MgO (x = 20, 30, 63, and 70 wt.%). The process of impregnation was used to prepare the catalysts. For characterization, N₂-physisorption, XRD, H₂-TPR, TGA, and Raman spectroscopy techniques were employed. Among the examined catalysts, 5Ni/Al₂O₃ + 63%MgO was found the most active, where it showed ≅ 72% CH₄ conversion, 73% CO₂ conversion, and 0.82 H₂/CO mole ratio over 7 h of reaction. The MgO modifier was the primary component, which favorably affected both Ni dispersion and stability, for the good interaction between NiO and γ-alumina. The mono-supported samples displayed the lowest total hydrogen consumption. In TGA, the 5Ni/Al₂O₃ + 63%MgO exhibited a significant weight decrease (40%), reflecting its activity. Furthermore, the Raman spectroscopy analysis showed that the crystallinity of the carbon over this catalyst was more pronounced than the others.

The dry reforming of methane is a highly popular procedure since it can transform two of the most abundant greenhouse gases, methane and carbon dioxide, into useful syngases that can be further processed into valuable chemicals. To successfully achieve this conversion for the effective production of syngas, an optimal catalyst with advantageous physicochemical features must be developed. In this study, a variety of Ni-based catalysts supported by zirconia alumina (5Ni-10Zr + Al) were prepared by using the impregnation approach. Different loadings of Fe promoter were used, and the performances of the resulting catalysts in terms of activity and stability were investigated. The catalyst used in this study had an active metal component made of 5% Ni and x% Fe supported on 10ZrO₂ + Al₂O₃, where x = (1, 2, 3, and 4). The physicochemical characteristics of both freshly calcined and used catalysts were studied using a range of characterization techniques, such as: N₂ adsorption–desorption isotherms, XRD, H₂-TPR, Raman spectroscopy, TGA, and TEM. An investigation of the effects of the Fe promoter on the catalytic activity of the catalyst (5Ni + xFe-10Zr + Al) was conducted. Amongst the studied catalysts, the 5Ni + 3Fe-10Zr + Al catalyst showed the best catalytic activity with CH₄ and CO₂ conversions of 87% and 90%, respectively, and had an H₂/CO ratio of 0.98.