Hydrogen Production via Thermo Catalytic Decomposition of Methane over Bimetallic Ni-Cu/AC Catalysts: Effect of Copper Loading and Reaction Temperature

Abstract

 Abstract—This study investigated on the effect of copper loading on the catalytic performance of Ni/AC catalysts at various reaction temperatures. Cu loading was varied from 0%, 5%, 10% and 15%, and the reaction temperatures tested were 600° C, 750° C and 900° C. The reaction was carried out in a U-tube quartz plug flow micro-reactor, and allowed to proceed for 8 hours. The highest initial methane conversion of 29.95% was observed on the Ni/AC catalyst without Cu loading at 900° C. However, this catalyst rapidly deactivated after only 3 hours. On the other hand, the 6.7Ni-5Cu/AC catalyst at 900° had an initial methane conversion of 27%, but slower catalyst deactivation was observed. This is due to the positive effect of copper on the metallic Ni particles, enhancing the ability of the catalyst to accumulate carbon, thus increasing stability at high temperatures. Statistical analysis of the experimental data using two-way ANOVA method determined that for a 95% confidence interval, only reaction temperature had a significant effect on the activity of the Ni-Cu/AC catalysts, while Cu loading was an insignificant factor. XRD results showed the formation of Ni3C crystallite for all catalyst samples except 6.7Ni-5Cu/AC, which may have contributed to catalyst deactivation. Also, SEM images of the spent 6.7Ni-5Cu/AC catalyst, which exhibited the best catalytic performance, showed the formation of valuable filamentous carbon, which may be used extensively in many other fields of application.