Preparation and evaluation of Ni/γ-Al2O3 catalysts promoted by alkaline earth metals in glycerol reforming with carbon dioxide.

Glycerol is the main by-product in the biodiesel process and can be considered as a promising and renewable source for hydrogen generation through the reforming process. In this work, catalysts with 15 wt% Ni supported on 3 wt% M − Al 2 O 3 (M = MgO, CaO, SrO, and BaO) were prepared and employed in the glycerol dry reforming (GDR) reaction to produce hydrogen and carbon monoxide. The textural characteristics of the fresh and spent catalysts were determined using the ICP, BET, TPR, TPO, and SEM analyses. Based on the obtained results, the catalyst promoted by SrO had the highest catalytic activity. The results indicated that adding various alkaline-earth oxides into the catalyst support decreased the Ni crystalline size from 17.2 nm to 7.4–10.9 nm. Moreover, all promoted catalysts showed better catalytic performance and the promoted sample with 3 wt% SrO possessed higher stability than unpromoted catalyst during 20 h on stream. • 15 wt%. Ni catalysts supported on 3 wt%MO-Al 2 O 3 (M = Mg, Ca, Sr, and Ba) were prepared. • The catalysts were employed in glycerol dry (CO 2) reforming. • The crystallite sizes of the catalysts were in the range of 7.4–10.9 nm. • 15 wt%Ni/3 wt%SrO–Al 2 O 3 catalyst had the highest performance in glycerol dry reforming. • The addition of promoters resulted in a lower amount of deposited carbon. [ABSTRACT FROM AUTHOR]