One-pot synthesis of 3D surface-wrinkled PdAu nanospheres for robust alcohols electrocatalysis

Polyphosphide anion-mediated simultaneous P, Au co-alloying with Pd for anti-poisoning formic acid oxidation

An innovative polyphosphide route is developed to synthesize a series of P-doped PdAu ternary alloys. The alloying of P and Au optimizes the electronic structure and reduces the back-donation of d electrons to CO. Meanwhile, the generation of CO is largely inhibited by the highly selective direct pathway arising from the synergistic electron/ligand effect of Au and P, leading to a remarkable anti-poisoning capability for formic acid oxidation.

Enhanced Electrocatalytic Performance of the FePt/PPy-C Composite toward Methanol Oxidation

A novel FePt/PPy-C composite nanomaterial has been designed and investigated as a methanol oxidation reaction (MOR) electrocatalyst. The FePt nanoparticles with an average diameter of about 3 nm have been prepared by the co-reduction method and then loaded onto the PPy-C composite support. The electrocatalytic performance is affected by the composition of the FePt nanoparticles. The experimental results indicated that the Fe1.5Pt1/PPy-C catalyst exhibited excellent catalytic activity and stability for MOR, with mass activity and specific activity of 1.76 A mgPt-1 and 2.71 mA cm-2, respectively, which are 5.18 and 4.60 times higher than that of the commercial Pt/C catalyst. Density functional theory (DFT) has been employed to simulate the electrical structures of catalyst supports, and the mechanism of the methanol oxidation process has been further analyzed. The heterojunctions of the PPy-C interface could accelerate the electron migration from the electrocatalytic center to the electrodes. The possibility of methanol oxidation has been improved effectively, which can be confirmed by the d-band center and CO adsorption energy on FePt nanoparticles in the DFT calculation results.

Laser Irradiation Synthesis of AuPd Alloy with Decreased Alloying Degree for Efficient Ethanol Oxidation Reaction

The preparation of electrocatalysts with high performance for the ethanol oxidation reaction is vital for the large-scale commercialization of direct ethanol fuel cells. Here, we successfully synthesized a high-performance electrocatalyst of a AuPd alloy with a decreased alloying degree via pulsed laser irradiation in liquids. As indicated by the experimental results, the photochemical effect-induced surficial deposition of Pd atoms, combined with the photothermal effect-induced interdiffusion of Au and Pd atoms, resulted in the formation of AuPd alloys with a decreased alloying degree. Structural characterization reveals that L-AuPd exhibits a lower degree of alloying compared to C-AuPd prepared via the conventional co-reduction method. This distinct structure endows L-AuPd with outstanding catalytic activity and stability in EOR, achieving mass and specific activities as high as 16.01 A mgPd-1 and 20.69 mA cm-2, 9.1 and 5.2 times than that of the commercial Pd/C respectively. Furthermore, L-AuPd retains 90.1% of its initial mass activity after 300 cycles. This work offers guidance for laser-assisted fabrication of efficient Pd-based catalysts in EOR.

Synthesis of Solvent-Mediated Morphology-Controlled PdSn Alloy Nanocatalysts and their Application in Electrocatalysis of Ethylene Glycol and Ethanol

2D nanodendrites (NDs) and nanosheets (NSs) have been regarded as efficient nanocatalysts for enhancing the electrocatalytic performance due to their low coordinated sites and abundant electrocatalytic centers. Nevertheless, it remains challenging to construct advanced NDs and NSs in a single reaction system. Herein, by tuning the volume ratios of mixed solvents, the reduction and diffusion rate of Sn2+ on Pd NSs template was rationally controlled to prepare PdSn NDs and PdSn NSs. Ascribed to the open 2D nanostructure, high specific surface area, and robust synergistic effect, the as-prepared PdSn NDs and PdSn NSs exhibited distinguished electrocatalytic activities for ethylene glycol oxidation reaction (EGOR) and ethanol oxidation reaction (EOR), as well as commendable electrocatalytic durability, which were far superior to the Pd NSs and commercial Pd/C. In addition, the PdSn NDs exhibited enhanced reaction kinetics because the characteristic branch structure exposed a high density of active sites. This work may provide significant guidance for preparing excellent nanocatalysts with various morphological features by simply optimizing the content of the coexisting solvents.

Cu-Modified Palladium Catalysts: Boosting Formate Electrooxidation via Interfacially OHad-Driven Had Removal

Direct formate fuel cells have gained traction due to their eco-friendly credentials and inherent safety. However, their potential is hampered by the kinetic challenges of the formate oxidation reaction (FOR) on Pd-based catalysts, chiefly due to the unfavorable adsorption of hydrogen species (Had). These species clog the active sites, hindering efficient catalysis. Here, we introduce a straightforward strategy to remedy this bottleneck by incorporating Pd with Cu to expedite the removal of Pd-Had in alkaline media. Notably, Cu plays a pivotal role in bolstering the concentration of hydroxyl adsorbates (OHad) on the surface of catalyst. These OHad species can react with Had, effectively unblocking the active sites for FOR. The as-synthesized catalyst of PdCu/C exhibits a superior FOR performance, boasting a remarkable mass activity of 3.62 A mg-1. Through CO-stripping voltammetry, we discern that the presence of Cu in Pd markedly speeds up the formation of adsorbed hydroxyl species (OHad) at diminished potentials. This, in turn, aids the oxidative removal of Pd-Had, leveraging a synergistic mechanism during FOR. Density functional theory computations further reveal intensified interactions between adsorbed oxygen species and intermediates, underscoring that the Cu-Pd interface exhibits greater oxyphilicity compared to pristine Pd. In this study, we present both experimental and theoretical corroborations, unequivocally highlighting that the integrated copper species markedly amplify the generation of OHad, ensuring efficient removal of Had. This work paves the way, shedding light on the strategic design of high-performing FOR catalysts.