Tingwei An , Zixuan Zhang , Xu Ren , Keliang Wang , Ziwei Li , Min Li
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引用次数: 0
Abstract
Steam reforming of tar represents a cost-effective approach for tar removal in biomass gasification. Here, we developed a Ni-Fe/CeO2/CNT catalyst and unveil the effect of Fe for steam reforming of toluene (SRT) which is a representative tar model compound. The catalyst demonstrated exceptional stability (above 80 % toluene conversion, 3000 mmol/gcat/h H2 yield) over 50 h. The outstanding performance is attributed to the effect of Fe in forming Ni-Fe alloy with the highest reducibility, dispersion, Ni0 ratio, and increased sintering resistance, alongside enhanced electron transfer between Ni and Fe. Fe also promotes H2O adsorption, providing active oxygen for toluene conversion and carbon elimination. Finally, reaction mechanism was explored based on the in-situ DRIFTS and DFT calculations. DFT calculations revealed that Fe sites exhibit higher density of states, electrostatic potential, and d-band center than Ni sites, facilitating H2O coordination. Fe doping reduces energy barriers for H2O splitting and methyl dehydrogenation, while Ni promotes H2 desorption. The synergistic Ni-Fe interaction enables distinct activation of toluene and H2O, respectively. Comparative studies showed Ni/CeO2/CNT suffers from carbon deposition, while Fe/CeO2/CNT exhibits limited activity due to poor reducibility and low Fe0 content. These findings provide critical insights for designing stable Fe-based catalysts for efficient tar removal.
期刊介绍:
Applied Catalysis A: General publishes original papers on all aspects of catalysis of basic and practical interest to chemical scientists in both industrial and academic fields, with an emphasis onnew understanding of catalysts and catalytic reactions, new catalytic materials, new techniques, and new processes, especially those that have potential practical implications.
Papers that report results of a thorough study or optimization of systems or processes that are well understood, widely studied, or minor variations of known ones are discouraged. Authors should include statements in a separate section "Justification for Publication" of how the manuscript fits the scope of the journal in the cover letter to the editors. Submissions without such justification will be rejected without review.