Highly efficient submonolayer Pt-decorated Au nano-catalysts for formic acid oxidation

Abstract

A novel structure of catalyst, submonolayer Pt-decorated Au, has been synthesized with minimal use of Pt and shows markedly improved activity toward formic acid oxidation where it facilitates the direct oxidation of formic acid by suppressing the formation of poisonous species COads via the "ensemble" effect.

Au as an efficient promoter for electrocatalytic oxidation of formic acid and carbon monoxide: a comparison between Pt-on-Au and PtAu alloy catalysts

“…When the Pt/Au ratio is below 1:7.16, the pathway of FA oxidation transforms into dehydrogenation. It is in agreement with the observation by Kristian et al [30] who attributed such to a proposed ensemble effect for Pt-on-Au.…”

“…Obviously, the peak current density at O 1 (j O1 ) on Pton-Au is larger, and the peak current density at O 2 (j O2 ) relatively becomes lower than that on pure Pt toward FA oxidation (in Fig. 5a and Table 3), which is in agreement with the results of previous reports [29,30]. Especially, the M-1:10.22 catalyst of Pt-on-Au shows the highest j O1 (15.76 mA cm −2 ), which is~14 times higher than that of Pt/GCE.…”

“…Recently, various bimetallic Pt-Au catalysts with different structures, such as PtAu alloy [21,28], Pt-modified Au (Pt-on-Au) [29,30], and Au@Pt [31,32], show excellent catalytic activity toward FA oxidation. Park et al [33] found that the uniform Pt-on-Au nanoparticles showed higher electrocatalytic activities than the pure Pt electrocatalyst in the area-and mass-specific current densities.…”

“…Additionally, the surface composition of atomic Pt/Au ratio and the preparation method are significantly related to the electrocatalytic activity of bimetallic PtAu catalyst for FA oxidation reaction [13,[34][35][36]. In general, the high electrocatalytic activity of bimetallic PtAu catalyst has been ascribed to the special electronic effect [29,36,37], ensemble effect [11,20,30], and synergistic effect [34,38,39]. Many research findings have revealed that both Pt-onAu and PtAu alloy catalysts exhibited high electrocatalytic activity toward FA oxidation with much less CO ads than that on Pt catalyst surface.…”

Pt Sub-Monolayer on Au: System Stability and Insights into Platinum Electrochemical Dissolution

“…One of the suggested mitigation strategies is the utilization of Pt@M (Pt -shell, M -core) core/shell ORR catalysts with M usually Pd, Au, Ir, and other noble metals or first-row transition metals, aiming at improved activity and stability while reducing Pt content at the same time. 7,8 Due to enhanced Pt mass-and surface-area-normalized activity, [9][10][11][12][13] typical loadings of Pt in such catalysts can be significantly lower than those traditionally employed in commercial Pt/C-based catalysts. At the same time catalysts are supposed to have superior stability based on accelerated degradation tests, typically performed under rather mild conditions in half-cell rotating disc electrode investigations.…”