Structure-Activity Relationship in Ni/AlO–ZrO–CeO Catalysts for Steam Reforming of Glycerol to Hydrogen-Enriched Syngas

Nickel catalysts for glycerol steam reforming suffer from rapid deactivation, hindering renewable hydrogen-rich syngas production. Herein, we address this by designing Ni/AlO–ZrO–CeO (ACZ) catalysts where AlO content (20 vs. 75 mol.%) tunes Ni dispersion and stability. At 600°C with a 9:1 molar HO/glycerol ratio, Ni/75ACZ achieved 75% glycerol conversion and 50% H yield, maintaining stability over 7h. In contrast, Ni/20ACZ deactivated sharply (conversion dropped from 44 to 6%), attributed to sintering (Ni particle growth: from 30 to 34 nm) and amorphous carbon deposition (I/I = 1.2). The Ni/75ACZ sample formed graphitic coke (I/I = 1.0) that did not block active sites. This work demonstrates that AlO enrichment stabilizes Ni against sintering and enables tolerance to amorphous carbon, offering a cost-effective strategy for durable glycerol reforming catalysts.