Few‐Layer Ag‐Coated Ordered Mesoporous Pt Nanocrystals for Ethanol Oxidation

Abstract

Direct ethanol fuel cells have broad application prospects, but there are still some issues such as slow oxidation kinetics and poisoning effects of intermediates in the anodic ethanol reduction reaction (EOR). Herein, a series of few‐layer Ag‐coated ordered mesoporous Pt nanocrystals (Meso‐Pt@Ag) with different Ag shell thicknesses are prepared by combining hard templating and in situ reduction methods. Benefiting from the ordered mesoporous structure, the lattice strain, and the electronic synergistic effect induced by the core–shell structure, Meso‐Pt@Ag2 nanocrystals exhibit the best EOR performance with a mass activity of 10.01 A mgPt−1, which is 8.40‐fold of commercial Pt/C and 4.45‐fold of Meso‐Pt, respectively. And, Meso‐Pt@Ag2 nanocrystals also show the favorable toxicity resistance to carbonaceous intermediates and stability for EOR. Furthermore, theoretical calculations demonstrate that the Ag‐coated Pt core has more optimized deprotonation reaction kinetics and lower CO adsorption energy, indicating its better resistance to CO toxicity for EOR.

IrCo Nanoparticles Encapsulated with Carbon Nanotubes for Efficient and Stable Acidic Water Splitting

“…Moreover, the Co 0 2p 3/2 peak of IrCo@CNT/CC displays a positive shift of 0.10 eV as compared with that of Co@PC/CC, indicating that further alloying allows more electron transfer from Co atoms to Ir atoms in the IrCo alloyed NPs of IrCo@CNT/CC (Figure e). Accordingly, a negative shift of 0.29 eV can be observed in the Ir 4f XPS spectra of IrCo@CNT/CC as compared with that of IrCo@PC/CC, which is caused by the higher alloying degree of IrCo NPs in IrCo@CNT/CC, resulting in Ir atoms receiving more electrons from Co atoms in this sample (Figure d). , Consequently, there is a strong charge synergistic effect acting in IrCo alloyed NPs, which changes their electronic structures and potentially boosts the subsequent electrocatalytic reactions.…”

“…Accordingly, a negative shift of 0.29 eV can be observed in the Ir 4f XPS spectra of IrCo@ CNT/CC as compared with that of IrCo@PC/CC, which is caused by the higher alloying degree of IrCo NPs in IrCo@ CNT/CC, resulting in Ir atoms receiving more electrons from Co atoms in this sample (Figure 2d). 56,57 Consequently, there is a strong charge synergistic effect acting in IrCo alloyed NPs, which changes their electronic structures and potentially boosts the subsequent electrocatalytic reactions. S17b).…”

Mechanistic Investigations of Electrochemical Ethanol Oxidation Reaction by In Situ Raman Spectroscopy

“…To achieve this, alloying PGM with other elements such as Co, [26] Ag, [27] and Zn, [28] among others, has been identified as an effective strategy to bolster catalytic performance, attributed to the so‐called synergistic effect [29,30] . Moreover, morphological engineering has also emerged as a potent approach to augment the exposure of active sites, thereby enhancing the overall performance of EOR catalysts [31,32] . In summary, a myriad of EOR catalysts have been developed, each boasting unique catalytic performances and potentially distinct reaction pathways.…”

“…[29,30] Moreover, morphological engineering has also emerged as a potent approach to augment the exposure of active sites, thereby enhancing the overall performance of EOR catalysts. [31,32] In summary, a myriad of EOR catalysts have been developed, each boasting unique catalytic performances and potentially distinct reaction pathways. Comprehensive studies of these catalysts are imperative prior to their commercialization.…”

Length-tunable Pd2Sn@Pt core–shell nanorods for enhanced ethanol electrooxidation with concurrent hydrogen production

“…Pt and Pt-based catalysts have been widely recognized as highly efficient electrocatalysts for the EOR. 29–32 However, their practical application is severely hindered by the exorbitant cost of Pt. Additionally, these catalysts often suffer from rapid degradation during the EOR process due to the accumulation of carbonaceous intermediates on their surfaces.…”