Morphology effect of ceria support with hierarchical structure on the catalytic performance for nickel-based catalysts in dry reforming of methane

• CeO 2 supports with various morphologies were synthesized & used in Ni-based catalyst. • The most abundant oxygen vacancy of CeO 2 -D can effectively improve catalytic activity. • Ni/CeO 2 -D exhibited the highest Ni dispersion and a superior TOF value of CH 4 in DRM. • The hierarchical dumbbell-like structure of catalyst can promote SMSI & CH 4 cracking. CeO 2 is widely used as Ni-based catalyst support in methane dry reforming (DRM), and the hierarchical structure of the ceria behaves a favorable effect on the performance of the catalyst. Ceria with different morphologies, including dumbbell (CeO 2 -D), bouquet (CeO 2 -B) and shuttle (CeO 2 -S) shapes, are hydrothermally prepared, and the effect of ceria shape on the catalytic performance of Ni/CeO 2 in DRM is investigated by a fixed-bed tubular reactor. The results indicate that Ni/CeO 2 -D demonstrates the best reaction conversions & TOF value, whose conversions of CH 4 & CO 2 can reach 92% & 87%, respectively. Furthermore, a series of characterization results (XPS, H 2 -TPR and Raman) confirm that the Ni/CeO 2 -D own the abundant oxygen vacancies and strong metal-support interaction, which promote the reactivity of CH 4 and CO 2 , resulting in its most prominent catalytic performance. Additionally, Ni/CeO 2 -D possesses other distinct advantages due to its hierarchical dumbbell-like structure confirmed by high Ni dispersion (H 2 -TPD), abundant surface oxygen (H 2 -TPR) and sufficient basic sites (CO 2 -TPD).