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Glycerol dry reforming presents an intriguing approach for converting CO2, a greenhouse gas, and glycerol, a renewable resource, into syngas. This study delves into the impact of introducing 5 wt% of ZrO2, CeO2, La2O3, and Y2O3 to the Al2O3 support. Additionally, the study examines the influence of the optimal metal oxide ratio within the support formula on both structural properties and catalytic performance in the glycerol dry reforming process. To investigate these aspects, various catalyst supports were synthesized using a mechanochemical method. Subsequently, nickel-based catalysts were prepared through a wet impregnation technique. The catalysts underwent comprehensive characterization employing techniques such as XRD, BET, H2-TPR, CO2-TPD, TPO, and FESEM analyses to determine their physicochemical properties. The results demonstrated that the sample enhanced with 5 wt% ZrO2 exhibited remarkable performance metrics. Notably, it achieved a catalytic activity of 85.4% glycerol conversion at 650 ℃, while also displaying better stability and resistance to carbon deposition compared to the unpromoted catalyst throughout a 600 minutes reaction period. These enhanced attributes were attributed to the heightened specific surface area of the support (241.95 m2/gr), the effective dispersion of Ni on the support and the increase in basic sites.

This work is concentrated on designing of CO2 methanation process over nickel-based catalysts doped by different promoters (CuO, Cr2O3, Co3O4, Fe2O3, and MnO2) supported on CaO.2Al2O3 powder. The CaO-Al2O3 powder was fabricated by mechanochemical method, and catalysts were synthesized via a wet impregnation procedure. The characterization properties of all samples were tested by XRD, BET, TPR, FESEM, and EDS-mapping analyses. The optimum amount of NiO was selected at 10 wt% along with CaO:Al2O3 as support with the molar ratio of 1:2. The Co-doped catalyst showed the lowest pore size (9.4 nm) and the highest surface area (106 m2.g−1) among the promoted catalysts. The results exhibited that the Co3O4(3)-NiO(10)/CaO.2Al2O3 catalyst possessed superior catalytic performance in the CO2 methanation reaction. The results illustrated that the increase in cobalt oxide percentage up to 3 wt% improved catalytic performance. However, further augmentation in the Co3O4 from 3 to 7 wt% diminished the specific surface area. According to the performance tests, carbon dioxide conversion and methane selectivity were 83.1% and 99.5% at 450 °C under operating conditions (GHSV = 18,000 ml.gcat−1.h−1 and H2:CO2 = 4:1) over this catalyst. The processing conditions including calcination temperature, reduction temperature, GHSV, feed ratio, and long-term stability test were also examined over the selected catalyst. Outcomes revealed that CO2 conversion increased with a decrement in calcination temperature from 650° to 450°C. Also, chosen catalyst reduced at 650 °C showed the highest performance. Besides, catalytic performance enhanced by raising feed ratio (H2:CO2) from 2:1 to 5:1 and decreased with augmentation of GHSV from 12,000 to 30,000 ml.gcat−1.h−1. Moreover, Co3O4(3)-NiO(10)/CaO.2Al2O3 catalyst possessed high stability during 14 h time on stream.