Amorphous MoO_x with High Oxophilicity Interfaced with PtMo Alloy Nanoparticles Boosts Anti‐CO Hydrogen Electrocatalysis

Abstract

Advancing electrocatalysts for alkaline hydrogen oxidation/evolution reaction (HOR/HER) is essential for anion exchange membrane‐based devices. The state‐of‐the‐art Pt‐based electrocatalysts for alkaline HOR suffer from low intrinsic activities and severe CO poisoning due to the challenge of simultaneously optimizing surface adsorption toward different adsorbates. Herein, this challenge is overcome by tuning an atomic MoOx layer with high oxophilicity onto PtMo nanoparticles (NPs) with optimized Had, OHad, and COad adsorption for boosting anti‐CO‐poisoning hydrogen‐cycle electrocatalysis in alkaline media. For alkaline HOR, this catalyst exhibits high kinetics and an exchange current density of 3.19 mA µgPt−1 at 50 mV versus reversible hydrogen electrode and 0.83 mA cmPt−2, 10.3‐ and 3.8‐fold higher than those of commercial Pt/C, respectively. For alkaline HER, it achieves an unprecedented overpotential of 37 mV at 10 mA cm−2. Experimental and theoretical studies show that the orchestrated electronic and oxophilic regulation of the PtMo/MoOx interface NPs simultaneously optimizes Had and OHad adsorption for boosting alkaline hydrogen electrocatalysis, whereas reactive oxygen from the amorphous MoOx atomic layer lowers the CO oxidation reaction barrier, leading to superior anti‐poisoning ability even at 100 ppm CO.

Interface Engineering for the Enhanced Antipoisoning Property of Oxygen Reduction Reaction

“…Pd-TeO x -BiO x /C exhibit better antipoisoning property than the other catalysts mainly due to the presence of abundant amorphous BiO x with oxophilic property that could optimize the adsorption of CO and CH 3 OH. 15,29 The half-wave potential of Pd-TeO x -BiO x /C (0.896 V RHE ) is higher than those of Pd-BiO x /C (0.882 V RHE ), Pd/C (0.842 V RHE ), and commercial Pd/C (0.83 V RHE ) but lower than that of Pd-TeO x /C (0.906 V RHE ) (Figure 2f). Moreover, Pd-TeO x -BiO x /C also demonstrate a higher mass activity of 0.…”

Confinement Effects in Carbonized ZIF-Confined Hollow PtCo Nanospheres Enable the Methanol Oxidation Reaction

“…Pt-based electrocatalysts are easily poisoned by electrolytic intermediates (especially CO) that may block the Pt active sites and prevent further oxidation reactions. , In order to investigate the CO tolerance of PtCo@carbonized ZIF-8, CO-stripping measurements were obtained in acidic media. − As shown in Figures e and S16, a sharp oxidation peak can be observed in the range of 0.4–0.6 V in the first scan, while no oxidation peak appears in the second scan for both the PtCo@carbonized ZIF-8 and PtCo@ZIF-8 electrodes, indicating that a CO monolayer adsorbs onto the surface of Pt. − However, the initial oxidation potential of CO for PtCo@carbonized ZIF-8 is much lower than that of commercial Pt/C and PtCo@ZIF-8, suggesting that both the addition of the Co element and the confinement effects were able to weaken the adsorption of CO, thus improving the reaction kinetics of MOR …”

Mn‐Oxygen Compounds Coordinated Ruthenium Sites with Deprotonated and Low Oxophilic Microenvironments for Membrane Electrolyzer‐Based H2‐Production

“…Up to now, many efforts have been devoted to modulating the catalytic microenvironments of Ru-based catalysts to boost the desorption processes of H * /OH * on the active sites. [25][26][27] For example, the competitive adsorption strategy on Ru-SnO 2 sites and the H * transfer effects on Ru-WO 3-x sites have been demonstrated as effective approaches to facilitate the desorption of OH * and H * , respectively. [21,28] Simultaneously facilitating the H 2 recombination and the OH * desorption without compensation of water-dissociation energy barriers has been recognized as a potential pathway to enhance the HER kinetics; however, hardly any achievements have been made on controllably fabricating Ru catalytic sites with deprotonated and low oxophilic microenvironments.…”