Hierarchical Porous Carbon-PtPd Catalysts and Their Activity toward Oxygen Reduction Reaction

Abstract

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 2 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 2 g –1 and a current density for ORR of −1285 A g –1 at 2 mV s –1 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.

Improved Oxygen Reduction on GC-Supported Large-Sized Pt Nanoparticles by the Addition of Pd

“…PdPt nanoflowers exhibited improved electrocatalytic ORR activity compared to commercial Pt and Pd black catalysts [35], while PdPt alloy nanocubes showed enhanced electrocatalytic activity towards the ORR compared to Pd nanocubes [36]. Hierarchical porous carbon-PtPd catalysts, with different macropore sizes, showed a synergistic effect between PtPd nanoparticles and porous carbon supports with a high performance with respect to ORR activity [37].…”

One-Step Synthesis of Pt–Pd@ACF Catalyst in the Microreactor System for the Hydrogen Evolution Reaction

“…Among them, the most suitable candidates for catalysts are platinum and palladium, due to their excellent catalytic activity and selectivity, which made them favored for HER − and also for oxygen reduction reaction (ORR). , The most important issue for catalytic performance is the composition, relevant size, shape, and crystal structure of the used catalyst . Additionally, literature shows that bimetallic catalysts have better electrocatalytic properties − and thermal stability than their single metal counterparts …”

Exploring the Role of the Connection Length of Screen-Printed Electrodes towards the Hydrogen and Oxygen Evolution Reactions

“…There are many electrocatalysts that are reported for enhancing the HER and OER [ 5 , 6 , 7 ]. Numerous papers utilize solid electrodes such as glassy carbon [ 7 ], boron-doped diamond [ 8 ], nickel foam [ 5 ], and screen-printed electrodes to “electrically wire” their electrocatalysts [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ].…”

“…There are many electrocatalysts that are reported for enhancing the HER and OER [ 5 , 6 , 7 ]. Numerous papers utilize solid electrodes such as glassy carbon [ 7 ], boron-doped diamond [ 8 ], nickel foam [ 5 ], and screen-printed electrodes to “electrically wire” their electrocatalysts [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ]. Screen-printed electrodes (SPEs) are manufactured using well-known industrial printers by depositing a combination of layers onto a flat substrate which offers versatility in terms of electrode design, material compatibility, modifications with electrocatalysts, but yet offers highly economical, mass-producible and highly reproducible sensors [ 20 ].…”