Novel highly efficient Ni-based mesoporous alumina-silica supported catalysts for methane dry reforming: Influence of nickel loading

In this study, the dry reforming of methane (DRM) was examined over the Ni/Al2O3-SiO2 catalysts with various nickel contents for the syngas production. The mesoporous nanocrystalline aluminosilicate with a high surface area (180.87 m2. g-1) was utilized as support for preparing the nickel-based catalysts by the wet impregnation method. The XRD, BET, H2-TPR, TPO, and FESEM analyses were performed to characterized the calcined catalysts. The obtained results indicated that the catalyst efficiency was enhanced by increasing the nickel loading values from 5 to 15 wt%, while the sample with 20 wt% Ni showed a lower efficiency compared to the 15 wt% Ni catalyst. The catalyst with 15 wt% Ni loading showed the best activity (XCO2=79%, XCH4=74.5%) and stability (activity drop for CH4 approximate to 2.7% and CO2 approximate to 0.3%) at 700 degrees C for 5 h. Also, the effects of the operational conditions, such as GHSV, CH4/CO2 ratio, long-term stability, reduction and calcination temperatures were studied. As GHSV changed from 12000 to 30000 ml/h.gcat, both conversions were declined. Also, the CO2 conversion was increased and the CH4 conversion was decreased by increasing the feed molar ratio (CH4: CO2) from 0.5 to 2. A constant syngas generation was obtained in long-term stability test of the reduced catalyst, which had no variation in activity during 10 h of reaction. In addition, there was no significant difference in results when the calcination (550, 650, and 750 degrees C) and reduction temperatures (600, 700, and 800 degrees C) were varied.

Automated summary

This study investigated the effects of Ni/Al2O3-SiO2 catalysts with different nickel contents on the dry reforming of methane (DRM) for syngas production. The results showed that the catalyst with 15 wt% Ni exhibited the best activity and stability. Furthermore, the operational conditions and reduction temperature had an impact on the reaction results.