Mechanochemical preparation method for the fabrication of the mesoporous Ni-Al2O3 catalysts for hydrogen production via acetic acid steam reforming

Ni(x)-Al2O3 (x = 5, 7.5, 10, 12.5, 15, 17.5, and 20 wt%) catalysts were fabricated by the mechanochemical way, and the samples were used in acetic acid steam reforming. The results showed that all prepared samples have excellent features with a high BET area in the range of 185-215 m2 g-1. Based on the founding results, the reducibility degree of the studied samples was enhanced by raising the nickel content to 17.5 wt%. The activity results revealed that the catalyst with 17.5 wt% Ni showed the best performance, and the acetic acid conversion and hydrogen yield reached 93% and 35% at 450 degrees C over this sample, respectively. Also, the agglomeration of particles at higher calcination temperatures led to the decrease in acetic acid conversion by increasing the Tcalcination from 700 to 900 degrees C. Furthermore, the results demonstrated that the catalytic activity improved by a decrease in GHSV value from 24000 to 12000 ml h-1.g-cat1 and an increase in the S/C molar ratio from 1:1 to 5:1. The influence of reduction temperature on the catalytic performance was also studied over the selected catalysts, and the results indicated that the sample under reduction temperature of 700 degrees C displayed the highest efficiency in the acetic acid steam reforming, which was related to the existence of more active sites and more acetic acid adsorption on the catalyst surface.