Salgado J R C, Quintana J J, Calvillo L, Lázaro M J, Cabot P L, Esparbé I, Pastor E
Departamento de Química Física, Universidad de la Laguna, Avda. Astrofísico Francisco Sánchez, 38071, La Laguna, Santa Cruz de Tenerife, Spain.
Phys Chem Chem Phys. 2008 Dec 7;10(45):6796-806. doi: 10.1039/b809227c. Epub 2008 Oct 8.
The influence of different functionalization treatments of the support on the electrocatalytic activity towards CO and methanol oxidation at platinum nanoparticles deposited on ordered mesoporous carbons (OMC) has been studied for the first time. Before deposition of the metal, the carbon support was functionalized applying several procedures, with the purpose to generate oxygenated groups for anchoring the Pt nanoparticles by the formic acid (FM) and borohydride (BM) reduction methods. Good dispersion of the catalyst was obtained in all cases. It has been shown that particle size, and consequently the lattice parameter and metal surface area, depends on the functionalization treatment employed. CO and methanol electrooxidation was studied at all prepared catalysts applying cyclic voltammetry. It was observed that CO stripping occurs at more negative potentials (around 0.10-0.15 V) with these supports with respect to Vulcan XC-72 supported catalysts, and the best results for both methods were achieved with OMC functionalized with concentrated nitric acid for 0.5 h. This carbon support presents a higher amount of oxygenated groups without the loss of the ordered structure. In situ infrared studies have been performed for the first time with this type of catalyst, showing that the effect of the carbon support on the CO oxidation potential is similar to the presence of a second metal as Ru under the same experimental conditions. Methanol electrooxidation is also dependent on the nature of the support, as proved from both cyclic voltammetry and chronoamperometry. In this case, results depend on the method of nanoparticles preparation and seem to be better for BM.
首次研究了载体的不同功能化处理对负载在有序介孔碳（OMC）上的铂纳米颗粒对CO和甲醇氧化的电催化活性的影响。在沉积金属之前，通过几种方法对碳载体进行功能化处理，目的是通过甲酸（FM）和硼氢化物（BM）还原法生成含氧基团以锚定Pt纳米颗粒。在所有情况下均获得了良好的催化剂分散性。结果表明，粒径以及晶格参数和金属表面积取决于所采用的功能化处理。应用循环伏安法对所有制备的催化剂进行了CO和甲醇电氧化研究。观察到，相对于Vulcan XC-72负载的催化剂，使用这些载体时，CO脱附发生在更负的电位（约0.10 - 0.15 V），并且用浓硝酸功能化0.5 h的OMC在两种方法中均取得了最佳结果。这种碳载体具有较高含量的含氧基团且有序结构未损失。首次对这种类型的催化剂进行了原位红外研究，结果表明在相同实验条件下，碳载体对CO氧化电位的影响类似于第二种金属Ru的存在。甲醇电氧化也取决于载体的性质，这从循环伏安法和计时电流法都得到了证实。在这种情况下，结果取决于纳米颗粒的制备方法，并且对于BM似乎更好。
