Boosting alcohol electro-oxidation reaction with bimetallic PtRu nanoalloys supported on robust Ti0.7W0.3O2 nanomaterial in direct liquid fuel cells

Platinum–Copper Bimetallic Nanodendritic Electrocatalyst on a TiO2-Based Support for Methanol Oxidation in Alkaline Fuel Cells

“…Apart from carbon corrosion, the limited abundance and exorbitant cost of Pt also obstructed the eventual practical commercialization of DMAFCs. , Developing the Pt-based nanoalloys has sparked significant interest as an efficient approach to boost the employment efficiency of platinum atoms and decrease the catalyst price. , Among the Pt–M alloys, the PtCu nanoalloy emerges as a robust electrocatalyst for fuel-cell technologies because of the inexpensive cost and good electrocatalytic activity of Cu. ,, According to the previous experimental results ,, and density functional theory calculations, the Pt 3 Cu nanoalloy with the (111) crystal surface can drastically decrease the CO adsorption energies that assigned to the downshift in the d-band center in Pt after alloying with Cu, resulting in suppressing the CO–Pt bonding and thus improving the CO-tolerance and electrocatalytic performance for MOR. Additionally, the tuning structure and morphologies of the Pt-based electrocatalyst have also been evidenced to be another efficient way to boost the electrocatalytic performance of platinum-based nanocatalysts. ,,,, The dendritic-like nanostructures had unique properties of large density of low-coordinated atoms and kinks and great surface area, which provide more active sites on the surface compared to spherical-like nanocatalysts and low-index facet nanostructures. ,,,, …”

Enhanced formic acid electro-oxidation reaction over Ir,N-doped TiO2-supported Pt nanocatalyst

“…Another peak at ∼0.8 V RHE was attributable to the CO ads oxidation process, and the Pt/Ir,N-doped TiO 2 catalyst exhibited the CO ads onset potential and CO ads oxidation potential at 0.68 and 0.83 V RHE , which were significantly shifted to negative potential in comparison with the Pt/C (0.82 and 0.89 V RHE , respectively). This suggested superior CO-tolerance of the Pt/Ir,Ndoped TiO 2 electrocatalyst, which was ascribable to the strong interplay between Pt NPs and TiO 2 -based material, reducing the CO adsorption on the catalyst surface, thereby releasing more active sites for the FAOR of the Pt/Ir,N-doped TiO 2 [8,56]. The electrochemical surface area (ECSA) of all studied FAOR catalysts was calculated based on the COstripping charge from the CO-stripping curves by equation (2) [57,58]:…”

Lattice Strain and Composition Effects on the Methanol Oxidation Performance of Platinum–Ruthenium–Nickel Ternary Nanocatalysts

“…43,44 The mass activity/specific activities of the Pt S2), reflecting the efficacious MOR and less poisoning intermediates produced in the backward potential scan by adding the Ni atom, leading to the enhanced anti-COtolerance of Pt-based ternary catalysts. 3,36,45 To consider the reaction kinetics of all studied MOR catalysts, electrochemical impedance spectroscopy (EIS) was carried out in the frequency range from 0.1 to 10 5 Hz at the 0.4 V RHE potential, as shown in Figure 4d. The corresponding equivalent circuit included solution resistance (R s ), high-frequency constant phase element (Q 1 ), charge-transfer resistance (R ct ), and constant phase element related to adsorbed reaction intermediates (Q 2 and R 0 ).…”

“…In addition, the MOR performance of the Pt 60 Ru 20 Ni 20 /C catalyst also was higher than the Pt 70 Ni 30 /C catalyst (Figure S4), indicating the enhanced MOR performance of the as-made Pt-based ternary alloy due to the formation of synergistic effects of compounds. − For as-made PtRuNi/C catalysts, their MOR performance decreased when the too-large Ni content, like in Pt 50 Ru 20 Ni 30 , can be assigned to the reduced Pt active sites, thereby inhibiting the methanol oxidation activity. At the suitable Ni content, Pt-based alloys possessed sufficient Pt sites for enhancing the kinetic of the methanol dehydrogenation step, thereby boosting the MOR activity. , What is more, the ratios between forward and backward current peaks (i.e., I f / I b ratio) of the Pt 70 Ru 30 /C, Pt 70 Ru 20 Ni 10 /C, Pt 60 Ru 20 Ni 20 /C, and Pt 50 Ru 20 Ni 30 /C catalysts were 1.39, 1.43, 1.57, and 1.49 (Table S2), reflecting the efficacious MOR and less poisoning intermediates produced in the backward potential scan by adding the Ni atom, leading to the enhanced anti-CO-tolerance of Pt-based ternary catalysts. ,, To consider the reaction kinetics of all studied MOR catalysts, electrochemical impedance spectroscopy (EIS) was carried out in the frequency range from 0.1 to 10 5 Hz at the 0.4 V RHE potential, as shown in Figure d. The corresponding equivalent circuit included solution resistance ( R s ), high-frequency constant phase element ( Q 1 ), charge-transfer resistance ( R ct ), and constant phase element related to adsorbed reaction intermediates ( Q 2 and R 0 ) .…”

“…Alloying Pt with Ru is one of the most well-known and advanced nanomaterials to address detriments (i.e., CO poisoning, sluggish reaction kinetics, etc.) of the commercially available C-supported Pt catalyst for the anodic methanol oxidation reaction (MOR) process in direct methanol fuel cells, which are a potential substitute power source for energy-related applications. − In the PtRu catalyst system, Ru sites are more active than Pt in the water-discharge process at a negative potential to form hydroxyl groups, serving as activators to boost the CO ads oxidation step on Pt active sites, thereby releasing more Pt surface and enhancing the MOR rate. − In addition, Abruña et al reported that the interatomic distance between Pt and neighboring Ru atoms played an important role in an efficient interaction between Pt-CO ads and Ru–OH ads species to generate a transition state (Pt-CO ads ···OH ads -Ru) for the oxidation of the CO ads during the MOR . Although the PtRu catalyst can reduce the Pt content and enhance the overall MOR efficiency, their electrochemical durability is restricted by the component leaching in strongly acidic media. , Also, Ru metal belongs to the Pt-group metal, which is a major challenge for the widespread commercialization of the PtRu catalyst.…”