Sub‐Monolayer YO_x/MoO_x on Ultrathin Pt Nanowires Boosts Alcohol Oxidation Electrocatalysis

Abstract

A crucial issue restricting the application of direct alcohol fuel cells (DAFCs) is the low activity of Pt‐based electrocatalysts for alcohol oxidation reaction caused by the reaction intermediate (CO*) poisoning. Herein, a new strategy is demonstrated for making a class of sub‐monolayer YOx/MoOx‐surface co‐decorated ultrathin platinum nanowires (YOx/MoOx–Pt NWs) to effectively eliminate the CO poisoning for enhancing methanol oxidation electrocatalysis. By adjusting the amounts of YOx and MoOx decorated on the surface of ultrathin Pt NWs, the optimized 22% YOx/MoOx–Pt NWs achieve a high specific activity of 3.35 mA cm−2 and a mass activity of 2.10 A mgPt−1, as well as the enhanced stability. In situ Fourier transform infrared (FTIR) spectroscopy and CO stripping studies confirm the contribution of YOx and MoOx to anti‐CO poisoning ability of the NWs. Density functional theory (DFT) calculations further reveal that the surface Y and Mo atoms with oxidation states allow COOH* to bind the surface through both the carbon and oxygen atoms, which can lower the free energy barriers for the oxidation of CO* into COOH*. The optimal NWs also show the superior activities toward the electro‐oxidation of ethanol, ethylene glycol, and glycerol.

Supported Sub‐Nanometer Clusters for Electrocatalysis Applications

“…Reproduced with permission. [82] Copyright 2021, Wiley-VCH. g) The mechanism illustration change of Ir clusters and the transformation of α-Co(OH) 2 to β-CoOOH phase during OER.…”

“…Guo and co-workers proposed a sub-monolayer YO x /MoO x codecorated ultrathin platinum nanowires to catalyze the methanol oxidation with a high specific and mass activity of 3.35 mA cm −2 and 2.10 A mg Pt −1 , respectively (Figure 4d). [82] The key problem of reaction intermediate (CO*) poisoning to Pt in alcohol oxidation reaction is efficiently solved by the decorated sub-monolayer YO x /MoO x , in which the high oxyphilic Y and Mo allow COOH* to bond with both carbon and oxygen atoms. As shown in Figure 4e, the YO x /MoO x can transfer the CO* adsorption from linear mode (CO L ) to bridge mode (CO B ), which can lower the energy barrier of CO* to COOH* on the YO x /MoO x -Pt surface for efficient CO oxidation (Figure 4f).…”

“…Bottom is the adsorption for CO* and COOH* on YO x /MoO x decorated Pt surfaces. Reproduced with permission [82]. Copyright 2021, Wiley-VCH.…”

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

“…[17,[21][22][23][24] On the other hand, surface modification of Pt nanocrystals via adatoms, deposited atoms, or doped atoms significantly improve the electrocatalytic properties due to the geometric and electronic effects, but unfortunately, the active sites involved are usually distributed randomly. [25][26][27][28][29][30][31][32][33][34][35][36] Therefore, engineering multicomponent nanocatalyst by combining the isolation and surface modification of Pt atoms via certain metals is expected to produce highly efficient Pt-based electrocatalysts toward MOR.…”

Ir nanoclusters/porous N-doped carbon as a bifunctional electrocatalyst for hydrogen evolution and hydrazine oxidation reactions

“…3–5 However, the pivotal bottleneck is the intrinsically sluggish kinetics of the anodic oxygen evolution reaction (OER; 4OH − = O 2 + 2H 2 O + 4e − , 1.23 V, vs. reversible hydrogen electrode, RHE), resulting in enormous energy wastage and high cost. 6,7 Encouragingly, the hydrazine oxidation reaction (HzOR; N 2 H 4 + 4OH − = N 2 + 4H 2 O + 4e − , −0.33 V, vs. RHE) instead of the anodic OER has demonstrated great viability for achieving energy-saving H 2 production, obtaining H 2 at a much smaller voltage in the overall hydrazine splitting (OHzS) process. 8–10 Therefore, developing highly efficient bifunctional HER and HzOR electrocatalysts with high stability is urgently needed to achieve practical applications of energy-efficient hydrogen generation via OHzS.…”