Surface Engineering of PtSe₂ Crystal for Highly Efficient Electrocatalytic Ethanol Oxidation

The development of efficient electrocatalysts for ethanol oxidation reaction (EOR) is crucial for the potential commercialization of direct ethanol fuel cells, yet it faces significant challenges between catalytic performance and cost-effectiveness. 2D materials have recently emerged as a promising group of electrocatalysts due to their large surface area, efficient charge transport, tunable band structures, and excellent catalytic activity. In this study, the novel 2D layered noble-metal dichalcogenide, PtSe₂, is explored for efficient ethanol oxidation electrocatalysis from a microscopic perspective based on an on-chip microelectrochemical platform. While pristine PtSe₂ demonstrates similar EOR activities to Pt, argon plasma treatment significantly enhances the performance on EOR activity, I_f/I_b ratio, onset and peak potentials, and durability. Detail investigations reveal that plasma treatment results in the exposure of PtSe₂ surface, which is responsible for significantly enhanced EOR activity and poison-resistance as also confirmed by theoretical calculations. In situ electrical transport measurements for monitoring the catalyst surface intermediates, elucidate that both optimized OH_ads coverage and appropriate ethanol molecular adsorption on PtSe₂ are the key for the high performance. This work demonstrates noble-metal dichalcogenides as promising EOR electrocatalysts, and establishes on-chip electrocatalytic microdevice as a promising probing platform for diverse electrocatalytic measurements.