对苯醌修饰碳负载Pd催化剂的制备、表征及电催化氧化甲酸性能

制备了对苯醌(C_6H_4O_2)修饰Vulcan XC-72碳载体负载Pd催化剂(Pd/C-b),通过X-射线衍射(XRD)、拉曼光谱(Raman)、X-射线光电子能谱(XPS)和透射电镜(TEM)对碳载体及催化剂进行了表征,并用循环伏安法(CV)和计时电流法(CA)对其电催化氧化甲酸性能进行了测试。结果表明,对苯醌修饰没有改变碳载体结构及其石墨化程度;相对于未修饰的碳载体,修饰后的碳载体表面含氧量增加,其表面负载的Pd金属粒子粒径更小,分布更均匀;Pd/C-b催化剂的电催化氧化甲酸性能明显改善,抗CO中毒能力也有所增强。

Shape impact of nanostructured ceria on the dispersion of Pd species

The shape impact of nanostructured ceria on the dispersion of Pd species was investigated by analyzing the atomic configuration and the bonding environment of Pd species over spherical and cubic ceria particles,using STEM and XPS.Amorphous Pd particles of about 2.0 nm,with a substantial amount of tiny Pd species,dispersed on spherical ceria,primarily due to the enriched surface oxygen vacancies that bonded the Pd species tightly.While faceted Pd particles of about 2.9 nm located on cubic ceria with distinct interfaces where Pd atoms embedded into the ceria lattice.The crystalline Pd particles on ceria cubes were highly active and stable for methane combustion that occurred on the metal surface via a facile PdO/Pd redox cycle;while the amorphous Pd particles on spherical ceria particles were featured by a significantly higher activity and stability towards CO oxidation,where the Pd-ceria interface served as the active sites.

氮磷双掺杂碳负载钯催化剂的制备及其对甲酸电催化氧化性能

在800℃高温焙烧下制备了氮磷双掺杂的VulcanXC-72碳载体(C-NP-800),并通过改进的液相浸渍还原法制备了氮磷掺杂碳负载钯催化剂(Pd/C-NP-800)。通过XRD、XPS、EDS、TEM和Raman物理表征及循环伏安法和计时电流法等电化学方法对其电催化氧化甲酸性能进行测试。结果表明,氮磷掺杂的碳负载钯催化剂有更小的Pd金属粒子粒径,对甲酸电催化氧化活性和稳定性均有提高,抗CO中毒能力也有所增强。