Abstract In this work, natural limonite (NL) was selected as the precursor of hematite (H) to prepare the Ni-based catalysts (Nix/H) for catalytic cracking of toluene. The influences of nickel loading and reaction temperature on catalytic cracking of toluene as well as the lifetime of catalyst were evaluated and the gas products were determined. The catalysts before and after catalytic cracking were characterized by XRD (X-ray diffraction), H 2 -TPR (H 2 temperature-programmed reduction), TEM (Transmission electron microscopy), XPS (X-ray photoelectron spectroscopy). The results showed that the catalytic activity of Nix/H was obviously improved after the Ni addition due to the formation of Ni-Fe alloy. Toluene conversion increased at first with increasing of Ni loading from 0 to 6% and then decreased from 6 to 10%. High toluene conversion of 96% and stability were achieved as the Ni loading was 6% at the reaction temperature of 800 °C. Meanwhile, toluene was mainly decomposed into CO, H 2 , CH 4 , CO 2 and hematite was transformed into magnetite due to the consumption of active lattice oxygen during the catalytic cracking reaction. However, the decrease in catalytic activity of Nix/H with the increase of reaction time should be attributed to the metal carbide type coke formation.

中文翻译：

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Ni负载赤铁矿催化剂的绿色合成，用于催化裂解甲苯作为生物质焦油模型化合物生产合成气

摘要 本研究选择天然褐铁矿（NL）作为赤铁矿（H）的前驱体，制备了用于甲苯催化裂化的镍基催化剂（Nix/H）。评价了镍负载量和反应温度对甲苯催化裂化和催化剂寿命的影响，并测定了气体产物。通过XRD（X射线衍射）、H 2 -TPR（H 2 程序升温还原）、TEM（透射电子显微镜）、XPS（X射线光电子能谱）对催化裂化前后的催化剂进行表征。结果表明，由于形成Ni-Fe合金，加入Ni后Nix/H的催化活性明显提高。随着Ni负载量从0％增加到6％，甲苯转化率首先增加，然后从6％减少到10％。在 800 °C 的反应温度下，Ni 负载量为 6%，因此甲苯转化率高达 96%，并且稳定性高。同时，甲苯主要分解为CO、H 2 、CH 4 、CO 2 ，​​赤铁矿在催化裂化反应过程中因消耗活性晶格氧而转化为磁铁矿。然而，随着反应时间的增加 Nix/H 催化活性的降低应归因于金属碳化物型焦炭的形成。