Modulating Electronic Structure of an Au‐Nanorod‐Core–PdPt‐Alloy‐Shell Catalyst for Efficient Alcohol Electro‐Oxidation

Abstract

are more convenient and secure to be transported and stored. However, the conversion efficiencies of these AORs are commonly inferior to hydrogen oxidation. This is partially due to the sluggish kinetics of multielectrons' transferred processes inside alcohols (e.g., methanol, ethanol, ethylene glycol, and glycerol). [7][8][9][10][11] In this regard, various catalysts of both noble and non-noble metals have been designed and synthesized to boost such sluggish AORs. Although noble metal catalysts (e.g., Pd, Pt, and Rh) are more expensive than non-noble metals (e.g., Ni, Co, and Mn), their more negative AOR onset potentials make them superior for the construction of DAFCs, [4,5,11] originating from their unique electronic structures. Among reported noble-based catalysts, those based on the Pt metal are regarded as the star electrocatalysts for the AORs in terms of their oxidation overpotentials and Tafel slopes. [12,13] Notably, their alloys with other metals (e.g., Ru, Ni, Co, Pd, Rh, and Au) exhibit strong adsorption capability toward OH species or a so-called bifunctional mechanism, leading to improved AOR performance. [14][15][16][17] On the other hand, the serious poisoning effect of the carbonaceous intermediates (especially CO) hinders dramatically the activity of the used catalysts (especially the Pt catalysts) and eventually leads to much reduced conversion efficiencies of the AORs. [18,19] In this context, the screwlike PdPt alloy nanowires [19] and PdPt alloy nanoparticles [20] have been employed to replace single metallic Pt catalysts for methanol electro-oxidation reaction (MOR). Originating from varied electronic structures that are induced by the addition of Pd atoms, these PdPt alloys have been confirmed as commendable MOR catalysts. Although the sizes and compositions of these catalysts have been tuned and the AOR performance on these catalysts has been explored, the performance of these bimetallic heterostructures/catalysts is still far away for their commercial applications. The catalysts featuring superior AOR performance over those reported are still highly demanded for the construction of high-performance DAFCs.It has been well known that the optimization of these noble-metallic heterostructures/catalysts with respect to their morphologies and exposed facets is helpful to enhance their catalytic performance. [21][22][23][24] Among various heterostructures, a catalyst with a core-shell structure has been attracted special attention. [25][26][27][28][29][30] Its structure and its catalytic activity of the shell are revealed to be highly dependent on the used core. [31][32][33][34] This is because the strain effect (expansion or compression) can be Direct alcohol fuel cells (DAFCs) utilize alcohol electro-oxidation reactions (AORs) to provide electricity, where catalysts with optimal electronic structures are required to accelerate sluggish AORs. Herein, an electrocatalyst with an Au-nanorod core and a PdPt-alloy shell is designed. Its electronic structures are modulated through epitaxial growth ...

Free-Standing, Interwoven Tubular Graphene Mesh-Supported Binary AuPt Nanocatalysts: An Innovative and High-Performance Anode Methanol Oxidation Catalyst

“…Moreover, for other TG/AuPt catalysts, the charge-transfer resistance increased with the decrease of Pt mass loading, indicating higher Pt mass loading yielded faster reaction kinetics for MOR. Our EIS results are similar to the works reported in [ 64 , 72 ].…”

“…The CO stripping CV curves ( Figure 8 ) contained the anodic peaks, resulting from the oxidation of the adsorbed CO on the surface of the catalysts [ 63 ]. Compared to TG/Pt 0.241 , the CO oxidation onset potentials ( E onset ) of the TG/Au x Pt y catalysts were much lower (see Table 2 ), indicating the importance of Au NPs on TG-based catalysts, which not only improve the growth of Pt NPs on TG but also promote the oxidization (or removal) of CO on the surface of catalyst, thus increasing the tolerance toward CO [ 64 , 65 ]. Moreover, E onset of TG/Au 42 Pt 58 is the highest, compared to those of the TG/Au x Pt y catalysts.…”

Metal‐Free Boron/Phosphorus Co‐Doped Nanoporous Carbon for Highly Efficient Benzyl Alcohol Oxidation

“…The different electronegativities of B/N atoms can affect the electronic structure of the P═O active site and surrounding C atoms. [ 4 , 28 ] Moreover, the longer the distance between the secondary heteroatom and P, the weaker effect of the heteroatom on the electronic structure of P═O active site. Thus, the electronic structures of the four abovementioned configurations were prioritized.…”

Multimetallic Metasurfaces for Enhanced Electrocatalytic Oxidations in Direct Alcohol Fuel Cells

“…[2] Thus, alternative materials and approaches to minimize the usage of Pt are needed to reduce the operational costs of DAFCs. [2,6,7] The most relevant type of DAFC is based on the methanol oxidation reaction (MOR). In this context, the coupling of MOR electrocatalysts with plasmonic (metallic) nanostructures has shown great potential in accelerating the reaction kinetics.…”