In Situ Probe of the Hydrogen Oxidation Reaction Intermediates on PtRu a Bimetallic Catalyst Surface by Core–Shell Nanoparticle-Enhanced Raman Spectroscopy

Abstract

In situ monitoring of the evolution of intermediates and catalysts during hydrogen oxidation reaction (HOR) processes and elucidating the reaction mechanism are crucial in catalysis and energy science. However, spectroscopic information on trace intermediates on catalyst surfaces is challenging to obtain due to the complexity of interfacial environments and lack of in situ techniques. Herein, core–shell nanoparticle-enhanced Raman spectroscopy was employed to probe alkaline HOR processes on representative PtRu surfaces. Direct spectroscopic evidence of an OHad intermediate and RuO x (Ru­(+3)/Ru­(+4)) surface oxides is simultaneously obtained, verifying that Ru doping onto Pt promotes OHad adsorption on the RuO x surface to react with Had adsorption on the Pt surface to form H2O. In situ Raman, XPS, and DFT results reveal that RuO x coverage tunes the electronic structure of PtRuO x to optimize the adsorption energy of OHad on catalyst surfaces, leading to an improvement in HOR activity. Our findings provide mechanistic guidelines for the rational design of HOR catalysts with high activity.

Applications of In Situ Raman Spectroscopy on Rechargeable Batteries and Hydrogen Energy Systems

“…Combining with XPS data and DFT calculation, we found that the different content of Ru doping tunes the catalytic activity of PtRu catalysts by regulating their electronic structure. Namely, the electronic effect also exists in the alkaline HOR mechanism [43] . The bifunctional mechanism for alkaline HOR was also observed in our Au@PtNi system [22]…”

Enhanced Performance of Sn@Pt Core-Shell Nanocatalysts Supported on Two Different Carbon Structures for the Hydrogen Oxidation Reaction in Acid Media

“…Elsewhere, several Pt-based core-shell nanostructures having Ru, Rh, or Au as the core have shown a high performance for the HOR, however in alkaline media [15][16][17][18]. Nevertheless, the advantages of using supported metal@Pt core-shell nanostructures with a lower Pt content compared to monometallic Pt/C, yet sustaining high performance, encourages the research on those nanocatalysts for the HOR in acid media.…”

Nickel‐Based Electrocatalysts for Hydrogen Oxidation Reaction Under Alkaline Electrolytes

“…Despite numerous efforts devoted to activating Ni-based catalysts for alkaline HOR, there are still several issues remaining. Firstly, the feasible surface reconstruction [63] needs to be taken into consideration, as well as the validation of catalytic roles for multicomponent catalysts. The enhancement mechanism of decorations and dopants may be related to the degree of surface variation, rather than just depending on the usual electronic interaction or alloy effect.…”