Morphology dependent? Elucidating the catalyst structures of Ni/Ce0.75Zr0.25O2 in the steam reforming of acetic acid
Ravipart Kun-udom, Salina Jantarang, Zehui Du, Boonyarach Kitiyanan, Thirasak Rirksomboon, Vissanu Meeyoo
Abstract
In this work, the steam reforming of acetic acid was catalyzed by Ni-based catalysts supported on ceria-zirconia of different morphological structures (nanopolyhedra, nanorods, and nanocubes). The altered shapes led to the variation in catalyst properties, such as the exposed planes, ease of Ni reduction/oxidation, and carbon removal, which affected its catalytic performance. Additionally, it was found that the exposed planes present in cubic {100} and rod structures ({100} and {110}) enhanced the formation of Ni0 and subsequently promoted the reforming reaction. Moreover, oxygen vacancies and mobility properties of {100} and {110} exposed planes can promote the oxidation reaction of carbon, resulting in a stable catalyst for the reforming of acetic acid. The results also showed that the type of depositing carbons was influenced by the support morphology. All the catalysts showed a 100% acetic acid conversion with the 15Ni/NC-CeZr (cubic structure) catalyst exhibited the highest hydrogen yield.