Cu含量对Pd-Cu/铝土矿CO氧化催化剂结构和性能的影响

利用资源丰富的天然铝土矿经NaOH溶液水热处理后焙烧，获得比表面积达174 m²·g^-1铝土矿载体，制备了双金属Pd-Cu为活性组分的催化剂，金属Pd负载量为0.5%（质量百分数），以CO氧化反应为探针反应，详细考察了Cu含量的变化对催化剂物化性能的影响。研究发现，Cu的引入有利于提高金属Pd的分散度，同时随着Cu含量的变化，金属Pd与Cu之间以及金属与铝土矿载体之间的相互作用随之改变。催化剂的CO氧化反应性能评价结果表明，Pd和Cu负载量分别为0.5%和4%的样品（PdCu₄/MB）催化反应性能最佳。结合表征结果认为，PdCu₄/MB的高活性归因于良好的Pd和Cu分散度，金属Pd、Cu以及金属与载体之间较强的相互作用。此外，CO-TPD表征结果说明较强的CO吸附能力和从载体中获取氧的能力也有利于提高PdCu₄/MB样品的CO氧化反应性能。

Effect of Cu Content on Structure and Catalytic Performance of Pd-Cu/Bauxite for CO Oxidation Reaction

We develop a bimetallic Pd-Cu catalyst that takes the advantage of Pd-Cu bimetal as active species and earth-abundant bauxite as support. The bauxite support with high surface area was obtained by hydrothermal NaOH aqueous solution treatment, and the amount of Pd is fixed to a low concentration of 0.5% (weight percentage) by incipient-wetness impregnation method. Their catalytic activity for CO oxidation reaction has also been studied. The effect of different Cu loading content on the chemical-physical properties of the as-prepared catalysts is investigated in detail. It is found that the dispersion of Pd species is promoted by the introduction of Cu species; and both Pd-Cu interaction and metal (Pd-Cu bimetals)-support (modified bauxite (MB) interaction are modulated by varying the Cu content. Furthermore, the catalytic activities with respect to the catalytic CO oxidation are performed, and the catalyst loaded with 0.5% Pd and 4% Cu (PdCu₄/MB) shows the highest catalytic activity. It is believed that the well dispersion of Pd and Cu, the strong interactions between the metals and the support as well as between Pd and Cu are responsible for the highest catalytic activity of PdCu₄/MB. Moreover, it can be concluded from the CO-TPD investigation that superior abilities in adsorption of CO and extraction of oxygen from the support are favor for high catalytic activity of PdCu₄/MB catalyst in CO oxidation.