The Structure of the Cobalt Oxide/Au Catalyst Interface in Electrochemical Water Splitting

Abstract

Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

Atomic‐Scale Observations of the Manganese Porphyrin/Au Catalyst Interface Under the Electrocatalytic Process Revealed with Electrochemical Scanning Tunneling Microscopy

“…The size of these new features is too small to detect (Figure S8, Supporting Information) by the general characterization tools, like scanning electron microscopy and energy‐dispersive X‐ray spectroscopy, in agreement with Daniel et al. [ 30a ] In addition, these new features are similar to a recent ex situ EC‐STM study of the decomposition of metalloporphyrin/Au(111) in NaOH after OER in terms of height, [ 33 ] and spatial area, [ 20b,c ] to the initial catalytically active structures. Furthermore, molecular oxygen was also produced in a moderate oxidation reaction via the manganese metal center, as confirmed by a higher ORR activity at ≈0.6 V (Figure S9, Supporting Information).…”

“…We thus propose that the real catalyst interrelates with other factors; especially in our case, where the Au surface led to the strong synergistic effects on catalytic activity. [ 29,34 ] As illustrated in Figure , at the second CV cycle, the peak at 0.95 V is associated with the Au lifting that is supposed to be induced by the chemisorption of reversible OH − ions on the Au surface, as followed by AuO formation at 1.2 V. [ 35 ] This phenomenon is directly explained by the loss of MnOEP arrangements resulting in the emerging Au on the surface in part (Figure S5, Supporting Information), as confirmed by the similar trend of the electrochemistry for bare Au (Figure S2, Supporting Information).…”

“…According to the literature, CoO x /Au(111) undertook the initial reorganization process to active oxide morphology in NaOH at the first potential sweep. [ 29 ] Therefore, we estimated that our pristine MnOEP/Au system also underwent an initial reorganization process, inducing the irreversible changes in morphology, structure, and chemical state. Moreover, given the enhanced OER activity even after the moderate potential sweeps (Figure S3, Supporting Information), the reorganization process is likely to occur in the moderate applied potential region.…”

Tuning the Electron Localization of Gold Enables the Control of Nitrogen‐to‐Ammonia Fixation

“…Small‐sized Au and Co islands were homogenously deposited onto the surface of Si using vapour deposition technology, and the Au NPs/CoO x layer (labeled as Au/CoO x ) sample was formed by using fast annealing of 800 °C in air (Figure a). The cobalt oxide layer was selected as a means of introducing Au 1+ active sites owing to a strong charge exchange between cobalt oxide and gold . In addition, we investigated the pure Au NPs on the Si wafer (labeled as Au sample) as a control experiment (Figure a).…”

Silica‐Free Synthesis of Mesoporous Co3O4/CoOxPy as a Highly Active Oxygen Evolution Reaction Catalyst

“…Hydrogen is one of the most important energy sources for the sustainable development of human society. Electrochemical as well as photoelectrochemical water splitting has proven to be a promising technique for hydrogen generation with high purity and large scale . However, the efficiency of water eletrolyzer is restricted by the slow kinetics of the oxygen evolution reaction (OER) at the electrode, which undergoes a four‐electron transfer process .…”