Abstract In the present study, we studied the hydrogen-rich gas production from catalytic pyrolysis of sawdust using various Fe-based catalysts derived from layered double hydroxide (LDH) precursor in a two-stage fixed-bed reactor. Specifically, we investigated the effect of support characteristics (Fe–Mg, Fe–Ca and Fe–Al) on the physicochemical properties and catalytic performances in relation to hydrogen production and coke formation. Various characterization techniques, such as XRD, SEM, BET, H2-TPR and TG-DTG temperature-programmed oxidation (TPO), were employed to thoroughly characterize the fresh and reacted Fe-based catalysts. It revealed that the support characteristics played an important role in determining the iron species form, textural properties and catalytic abilities of the resulting catalysts. The Al-supported Fe-based catalyst was found to be the most effective catalyst for hydrogen-rich gas production with the highest gaseous efficiency of 61.4 wt.%, gas yield of 598 mL/g biomass, H2 yield of 217 mL/g biomass, and H2/CO molar ratio of 2.5 at 700 °C. Based on the results of structural characteristics, this might be attributed to its fine particle, enhanced reducibility, high surface area and generation of surface acidity by introduction of Al form, which could provide efficient active sites for pyrolysis volatiles to crack and reform through a series of catalytic reactions. According to GC–MS experiment results, the Fe–Al catalyst was capable of selectively producing aromatic compounds, with the maximum yield as high as almost 100%. Therefore, the Fe–Al catalyst developed in this work could provide a promising route for hydrogen-rich gas production from catalytic pyrolysis of biomass.

中文翻译：

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用各种铁基催化剂热解木屑：载体特性对制氢的影响

摘要 在本研究中，我们研究了在两级固定床反应器中使用来自层状双氢氧化物 (LDH) 前驱体的各种铁基催化剂催化热解木屑产生的富氢气体。具体而言，我们研究了载体特性（Fe-Mg、Fe-Ca 和 Fe-Al）对与制氢和焦炭形成相关的物理化学性质和催化性能的影响。各种表征技术，如 XRD、SEM、BET、H2-TPR 和 TG-DTG 程序升温氧化 (TPO)，被用来彻底表征新鲜和反应后的 Fe 基催化剂。结果表明，载体特性在决定所得催化剂的铁物质形态、结构特性和催化能力方面起着重要作用。发现铝负载的铁基催化剂是最有效的富氢气体生产催化剂，最高气态效率为 61.4 wt.%，产气率为 598 mL/g 生物质，H2 产率为 217 mL/g 生物质和 H2/CO 摩尔比在 700 °C 时为 2.5。基于结构特征的结果，这可能是由于其颗粒细小、还原性增强、表面积大和通过引入铝形式产生表面酸性，可以为热解挥发物通过一系列裂解和重整提供有效的活性位点。催化反应。根据 GC-MS 实验结果，Fe-Al 催化剂能够选择性地产生芳香族化合物，最大产率高达近 100%。所以，