Gallic acid-assisted synthesis of Pd uniformly anchored on porous N-rGO as efficient electrocatalyst for microbial fuel cells

Abstract

The sluggish kinetic rate-limiting oxygen reduction reaction (ORR) at the cathode remains the foremost issue hindering the commercialization of microbial fuel cells (MFCs). Utilization of the effect of micromolecule conjugation and the synergistic effect between Pd nanoparticles and N-rGO (nitrogen-doped reduced graphene oxide) to stabilize a precious metal onto carbon materials is a promising strategy to design and synthesize highly efficient cathode catalysts. In this study, gallic acid is used to facilitate the coupling of palladium (Pd) with N-rGO to form GN@Pd-GA via a simple hydrothermal process. Notably, the as-synthesized GN@Pd-GA as a cathode catalyst shows an approximately direct four-electron feature and demonstrates a high ORR performance in 0.1 M KOH. Furthermore, the stability and methanol tolerance of GN@Pd-GA are superior to those of the commercial Pt/C catalysts. In addition, a maximum power density of 391.06 ± 0.2 mW m of MFCs equipped with GN@Pd-GA was obtained, which was 96.2% of the power density of MFCs equipped with a commercial Pt/C catalyst.

Yolk–Shell Fe/Fe4N@Pd/C Magnetic Nanocomposite as an Efficient Recyclable ORR Electrocatalyst and SERS Substrate

“…Two featured Raman peaks of carbon were observed at about 1350 and 1587 cm −1 , which were assigned to the D‐band and G‐band, respectively (Figure S9 of the Supporting Information, the Raman data were smoothened to get the thin red or black lines, then the values of I D / I G were obtained). The intensity ratio ( I D / I G ) was extensively employed to estimate the degree of disorder of carbon materials . The values of I D / I G for FFPC‐1, FFPC‐2, FFPC‐3, and FFC were calculated to be 0.96, 0.95, 0.95, and 0.92, respectively, implying the defective structure.…”

“…More interestingly, FFPC/NPCNFs‐3 exhibited the lowest electrolyte resistance ( R s ) and charge transfer resistance ( R ct ) (Figure S22, Supporting Information), which indicated that the conductivity of FFPC/NPCNFs related to the amount of palladium. In addition, the double layer capacitance ( C dl ) measurements (Figure S23, Supporting Information) were performed to evaluate the electrochemically active areas . The FFPC/NPCNFs‐3 and FFPC/NPCNFs‐2 showed C dl of 2.87 and 2.79 mF cm −2 , higher than that of FFPC/NPCNFs‐1 (2.34 mF cm −2 ), indicating that the FFPC/NPCNFs‐2 and FFPC/NPCNFs‐3 provided more exposed active surface area.…”

“…Nevertheless, the PdO bond strength was found to be too strong, resulting in a seriously unexpected coverage of oxygenated intermediates on Pd surface, which limits the availability of active sites for ORR . Among the solutions, strong metal–support interaction (SMSI) has been reported as a common method to optimize the ORR performance of Pd, e.g., Pd/GO, Pd/carbon nanotubes (CNTs), Pd/Mn 2 O 3 , Pd/TiO 2 ‐Vo, and PdH 0.706 /Ni‐B nanosheets . The enhanced ORR performance is generally believed to be attributed to the following reasons.…”

Preparation of Heteroatom‐Doped Carbon Materials and Applications in Selective Hydrogenation

“…The prepared catalyst then showed high activity and selectivity for the hydrogenation of C=C during hydrogenation of cinnamaldehyde, and maintained high performance after 5 cycles of use. Wu et al [73] . used small molecule binding effect and synergistic effect between Pd and N‐doped reduced graphene oxide (N‐rGO) to synthesize a cathode catalyst with designed physical structure and stabled Pd nanoparticles.…”

Electrochemical synthesis of AuPt nanoflowers in deep eutectic solvent at low temperature and their application in organic electro-oxidation

“…The methods for preparing the noble metal nanomaterials used in the modifying of electrodes have been widely developed 19–22 . In particular, bimetallic nanoparticles have been considered to be potential catalytic materials due to their specific properties and promising applications 23–30 .…”