Arias-Pinedo Ofelia Marilu, Cardenas Riojas Andy A, Pastor Elena, López Elvis O, Perez Geronimo, Archanjo Braulio S, Ponce-Vargas Miguel, Planes Gabriel Ángel, Baena-Moncada Angélica María
Laboratorio de Investigación de Electroquímica Aplicada, Facultad de Ciencias, Universidad Nacional de Ingeniería, Av. Túpac Amaru 210, Rímac, Lima 15333, Perú.
Departamento de Química, Instituto de Materiales y Nanotecnología, Universidad de La Laguna, Avenida Astrofísico F. Sánchez S/N, 38200, P. O. Box 456, La Laguna, Tenerife, Spain.
ACS Omega. 2022 Jun 7;7(24):20860-20871. doi: 10.1021/acsomega.2c01457. eCollection 2022 Jun 21.
PtPd bimetallic catalysts supported on hierarchical porous carbon (HPC) with different porous sizes were developed for the oxygen reduction reaction (ORR) toward fuel cell applications. The HPC pore size was controlled by using SiO nanoparticles as a template with different sizes, 287, 371, and 425 nm, to obtain three HPC materials denoted as HPC-1, HPC-2, and HPC-3, respectively. PtPd/HPC catalysts were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and high-resolution transmission electron microscopy. The electrochemical performance was examined by cyclic voltammetry and linear sweep voltammetry. PtPd/HPC-2 turned out to be the most optimal catalyst with an electroactive surface area (ESA) of 40.2 m g and a current density for ORR of -1285 A g at 2 mV s and 1600 rpm. In addition, we conducted a density functional theory computational study to examine the interactions between a PtPd cluster and a graphitic domain of HPC, as well as the interaction between the catalyst and the oxygen molecule. These results reveal the strong influence of the porous size (in HPC) and ESA values (in PtPd nanoparticles) in the mass transport process which rules the electrochemical performance.
开发了负载在具有不同孔径的分级多孔碳（HPC）上的PtPd双金属催化剂，用于燃料电池应用中的氧还原反应（ORR）。通过使用不同尺寸（287、371和425 nm）的SiO纳米颗粒作为模板来控制HPC的孔径，从而分别获得三种HPC材料，分别表示为HPC-1、HPC-2和HPC-3。通过扫描电子显微镜、X射线光电子能谱、X射线衍射和高分辨率透射电子显微镜对PtPd/HPC催化剂进行了表征。通过循环伏安法和线性扫描伏安法检测了电化学性能。结果表明，PtPd/HPC-2是最优化的催化剂，其电活性表面积（ESA）为40.2 m²/g，在2 mV/s和1600 rpm下ORR电流密度为-1285 A/g。此外，我们进行了密度泛函理论计算研究，以研究PtPd团簇与HPC石墨域之间的相互作用，以及催化剂与氧分子之间的相互作用。这些结果揭示了多孔尺寸（在HPC中）和ESA值（在PtPd纳米颗粒中）在决定电化学性能的传质过程中的强烈影响。
