Hexagonal PtBi Intermetallic Inlaid with Sub‐Monolayer Pb Oxyhydroxide Boosts Methanol Oxidation

Abstract

Engineering multicomponent nanocatalysts is effective to improve electrocatalysis in many applications, yet it remains a challenge in constructing well‐defined multimetallic active sites at the atomic level. Herein, the surface inlay of sub‐monolayer Pb oxyhydroxide onto hexagonal PtBi intermetallic nanoplates with intrinsically isolated Pt atoms to boost the methanol oxidation reaction (MOR) is reported. The well‐defined PtBi@6.7%Pb nanocatalyst exhibits 4.0 and 7.4 times higher mass activity than PtBi nanoplates and commercial Pt/C catalyst toward MOR in the alkaline electrolyte at 30 °C. Meanwhile, it also achieves a record‐high mass activity of 51.07 A mg–1Pt at direct methanol fuel cells operation temperature of 60 °C. DFT calculations reveal that the introduction of Pb oxyhydroxide on the surface not only promotes the electron transfer efficiency but also suppresses the CO poisoning effect, and the efficient p‐d coupling optimizes the electroactivity of PtBi@6.7%Pb nanoplates toward the MOR process with low reaction barriers. This work offers a nanoengineering strategy to effectively construct and modulate multimetallic nanocatalysts to improve the electroactivity toward the MOR in future research.

High‐Entropy Intermetallic PtRhBiSnSb Nanoplates for Highly Efficient Alcohol Oxidation Electrocatalysis

“…[ 54,59,60 ] To the best of our knowledge, the PtRhBiSnSb HEI nanoplates emerge as a state‐of‐the‐art electrocatalyst for AORs, and notably reach the record‐high MOR activities in alkaline electrolytes (Tables S1–S3, Supporting Information). [ 7,51,61–66 ]…”

“…In addition, as indicated by the XPS spectra in Figure 2g and Figure S11, Supporting Information, Pt and Rh atoms are mainly in the zero-valence state, while Bi, Sn, and Sb atoms are mainly in their oxidation states, due to the exposure of the easily oxidizable Bi, Sn and Sb atoms on the surface. [51][52][53][54][55] As shown in the Pt 4f XPS spectra of different Pt-based nanoparticles (Figure S12, Supporting Information), PtRhBiSnSb HEI nanoplates exhibit the lowest Pt 4f binding energy that could contribute to the weaker bonding strength between the catalyst surface and the adsorbed intermediate species, thus ensuring a higher electrocatalytic activity. [56,57] The uniform (PtRh)(BiSnSb) HEI nanoplates are obtained via a facile one-pot method, in which the Pt+Rh/Sn+Bi+Sb ratio should be kept at ≈1:1.…”

“…[54,59,60] To the best of our knowledge, the PtRhBiSnSb HEI nanoplates emerge as a state-of-the-art electrocatalyst for AORs, and notably reach the record-high MOR activities in alkaline electrolytes (Tables S1-S3, Supporting Information). [7,51,[61][62][63][64][65][66] The electrochemical durabilities of the highly active PtRh-BiSnSb HEI nanoplates and PtBiSnSb nanoplates are evaluated by sweeping 5000 CV cycles in the 1.0 m KOH + 1.0 m CH 3 OH solution. As shown in Figure 3e, after 5000 cycles, the current densities (calculated at the peak potentials of ≈0.85 V versus RHE) of PtRhBiSnSb and PtBiSnSb retain 70.2% and 62.7% of their initial values, respectively, while the Pt/C electrocatalyst retains 23.1%.…”

“…Thus, the classical CO-poisoning issue on the Pt-based catalysts is vanished on this PtRhBiSnSb HEI electrocatalyst, due to its superior tolerance toward CO-poisoning and optimized MOR pathway to avoid CO-poisoning. [51,[69][70][71][72][73] Adv. Mater.…”

Unveiling the Local Structure and Electronic Properties of PdBi Surface Alloy for Selective Hydrogenation of Propyne

“…Then, the growth will switch to the VW mode to form islands on the crystal surface . Previous reports have proven that Bi and Pd can form intermetallic structures; , therefore, inserting Bi atoms into Pd lattice to tune the electronic structure of Pd is feasible from the perspective of thermodynamics.…”