Abstract In this study, steam reforming of acetic acid over the Ni/γ-Al2O3 catalysts with varied nickel contents (from 2.5 to 40 wt%) was performed, aiming to investigate the effects of nickel loading on properties and catalytic behaviors of the catalysts. The results show that the interaction of nickel species with alumina varies with varied nickel loading. At lower nickel loadings, the nickel strongly interacting with alumina are the main species, while with the saturation of the reactive sites of alumina via loading more nickel, the proportion of the nickel species weakly interacting with alumina increased remarkably. Excess nickel on alumina can fill the pores, decreasing the reduction degree of nickel oxides, the specific area (from ca. 277 to 132 m2 g−1 with the increase of nickel loading to 40 wt%), the pore volume, and the pore diameters. Nickel loading also significantly affects the catalytic activity, stability of the catalyst and the resistivity towards coking. With the increase of nickel loading to 10 wt%, the activity of the catalyst reached a plateau. The further increase of nickel loading did not further increase the activity, but increased the stability and the tolerance towards the deactivation induced by coking. In addition, with higher nickel loadings, the coke formed has more large aromatic ring system.

中文翻译：

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Ni/Al 2 O 3 催化剂上乙酸蒸汽重整：镍负载量与催化剂性能和催化行为的相关性

摘要 本研究在不同镍含量（2.5～40 wt%）的Ni/γ-Al2O3催化剂上进行乙酸蒸汽重整，旨在研究镍负载量对催化剂性能和催化行为的影响。结果表明镍物质与氧化铝的相互作用随着镍负载量的变化而变化。在较低的镍负载量下，与氧化铝强相互作用的镍是主要物种，而随着氧化铝的反应位点通过负载更多的镍而饱和，与氧化铝弱相互作用的镍物种的比例显着增加。氧化铝上过量的镍可以填充孔隙，降低氧化镍的还原度、比表面积（随着镍负载量增加到 40 wt%，从大约 277 到 132 m2 g-1）、孔隙体积和孔隙直径。镍负载量也显着影响催化活性、催化剂的稳定性和抗结焦性。随着镍负载量增加到 10 wt%，催化剂的活性达到了平台期。镍负载量的进一步增加并没有进一步提高活性，而是提高了稳定性和对焦化引起的失活的耐受性。此外，镍载量越高，所形成的焦炭具有更大的芳环系统。但增加了对焦化引起的失活的稳定性和耐受性。此外，镍载量越高，所形成的焦炭具有更大的芳环系统。但增加了对焦化引起的失活的稳定性和耐受性。此外，镍载量越高，所形成的焦炭具有更大的芳环系统。