Surface Limited Redox Replacement Deposition of Platinum Ultrathin Films on Gold: Thickness and Structure Dependent Activity towards the Carbon Monoxide and Formic Acid Oxidation reactions

Bi-Underpotential/PtAu-bulk co-electrodeposition and subsequent Bi dissolution for the electrocatalytic oxidation and amperometric analysis of formaldehyde

A PtAuBi-UPD composite electrocatalyst modified glassy carbon electrode (GCE) is prepared via the simultaneous underpotential deposition (UDP) of Bi and bulk deposition of Pt and Au, followed by stripping of the accessible Bi, and it shows high performance for the electrocatalytic oxidation and amperometric analysis of formaldehyde.

Ultrathin Film PtxPd(1-x) Alloy Catalysts for Formic Acid Oxidation Synthesized by Surface Limited Redox Replacement of Underpotentially Deposited H Monolayer

This work emphasizes the development of a green synthetic approach for growing ultrathin film PtxPd(1-x) alloy catalysts for formic acid oxidation (FAO) by surface limited redox replacement of underpotentially deposited H sacrificial layer. Up to three-monolayers-thick PtxPd(1-x) films with different composition are generated on Au electrodes and characterized for composition and surface roughness using XPS and electrochemical methods, respectively. XPS results show close correlation between solution molar ratio and atomic composition, with slightly higher Pt fraction in the deposited films. The accordingly deposited Pt42Pd58 films demonstrated remarkable specific and mass activities of up to 35 mAcm−2 and 45 Amg−1 respectively, lasting for more than 1500 cycles in FAO tests. This performance, found to be better twice or more than that of pure Pt counterparts, renders the Pt42Pd58 films comparable with the frontrunner FAO catalysts. In addition, the best alloy catalyst establishes a nearly hysteresis-free FAO CV curve a lot earlier than its Pt counterpart and thus supports the direct FAO pathway for longer. Overall, the combination of high Pd activity and CO tolerance with the remarkable Pt stability results in highly active and durable FAO catalysts. Finally, this facile and cost-effective synthetic approach allows for scaling the catalyst production and is thus appropriate for foreseeable commercialization.