An investigation of the simultaneous presence of Cu and Zn in different Ni/Al2O3 catalyst loads using Taguchi design of experiment in steam reforming of methane

Abstract

Nowadays, increasing environmental pollution as well as restrictions on the use of fossil fuels have shifted the attention toward using hydrogen as a new source of clean and effective energy. Additionally, hydrogen and syngas are employed as feedstock for the production of valuable materials in the petrochemical industry. Methane steam reforming is the main procedure for the hydrogen and syngas production. In this study, Taguchi design of experiment (L9) was used to investigate the effects of simultaneous presence of copper (Cu) and Zinc (Zn) metals on different Ni/Al2O3 catalyst loads. It should be noted that some of the catalysts were characterized using XRD, BET, SEM and TGA analyses. According to the Taguchi design, it was concluded that the increment of Cu content enhances the catalyst stability and increases the CO selectivity. Increasing Zn content advocated CH4 conversion, H2 yield, and less selectivity toward the CO production. The XRD, BET and SEM test results revealed that the addition of Cu resulted in better distribution of active support phase. The TGA results indicated that the addition of Cu and Zn stabilized the catalyst activity; in this case, Cu was more effective than Zn. The overall results demonstrated that 15% load of Ni on Al2O3 support, simultaneous addition of Cu and Zn loads of 1% and 5%, respectively, enhanced the catalyst stability and activity and improved the catalyst performance in the selective hydrogen production as well.