Hydrogen-rich syngas production from acetic acid as bio-oil model compound: Effect of intermediate phases (La2NiO4, La2O3 and Ni) of LaNiO3 catalyst

Abstract

In biomass gasification, bio-oil is the main component of the condensable by-products. It is considered an attractive source for H2 production via steam reforming. This study conducted acetic acid as a bio-oil model compound with LaNiO3 perovskite catalyst due to its high oxygen vacancies and active sites. However, the perovskite structure of LaNiO3 catalysis can be destroyed by produced H2 gas, forming additional phases, including La2NiO4, La2O3 and Ni. The LaNiO3 and different phases were synthesized via a sol-gel method to probe its contribution and interaction with the H2 gas produced from steam reforming of acetic acid. Through 300 min of reaction in steam to carbon (S/C) ratio of 3, the results showed that reduced-LaNiO3 has stable H2 gas production, while the other phases decrease with time. In particular, CH4 is the main composition with the La2O3 phase. A series of characterization techniques, such as XRD, BET, XPS, SEM, TG, H2-TPR and (CO2 and O2)-TPD, were utilized to investigate fresh and used samples. The results showed that the LaNiO3-reduced phase has high oxygen storage capacity, oxygen mobility, oxygen vacancies and surface area, preventing coke deposition. In contrast, the LaNiO3 and La2NiO4 phases have poor coke deposition resistance.