New insights into evaluating catalyst activity and stability for oxygen evolution reactions in alkaline media

Abstract

New insights into efficient oxygen evolution were obtained by developing robust evaluation protocols and understanding interfacial behaviors.

Enhancing Energy Storage via TEA‐Dependent Controlled Syntheses: Two Series of Polyoxometalate‐Based Inorganic‐Organic Hybrids and their Supercapacitor Properties

“…Additionally, the current response of all of the redox peaks increased linearly with changing scan rates from 5–100 mV s −1 , as shown in the inset plots of Figure . A linear relationship was found between the anodic and the cathodic peak currents versus scan rates, which suggests that the compounds all exhibit surface‐controlled redox reactions at their electrodes …”

“…A linear relationship was found between the anodic and the cathodic peak currents versus scan rates, which suggests that the compounds all exhibit surfacecontrolled redox reactions at their electrodes. [27] (b) GCD measurements: GCD measurements were carried out to further test and compare the electrochemical capacitive performance of the six compounds based electrodes. The GCD curves of SiW-2 and W-1 at various current densities are displayed in Figures 8a and 8b, and that of other compounds are shown in Figure S14.…”

Ultrafine Metallic Nickel Domains and Reduced Molybdenum States Improve Oxygen Evolution Reaction of NiFeMo Electrocatalysts

“…Although ECSA calculation using the cyclic voltammetry method is a useful method to explore the interfacial behaviour of a catalyst, it could lead to quantitative errors. Typically, the double layer capacitance ( C dl ) gives the impedance involving in electron transfer and −OH adsorption at the catalyst–electrolyte interface, depending on the measurement conditions including the pH of an electrolyte, the conductivity of a catalyst, and the electrolyte permeability to a catalyst . Meanwhile, the discrepancy could come from the misestimate of C dl caused by the slow −OH diffusion on less accessible areas and the slow electron transfer on less conductive metal oxides, so that they could lead to the inaccurate description of the OER active sites for a catalyst.…”

Replacement of Ca by Ni in a Perovskite Titanate to Yield a Novel Perovskite Exsolution Architecture for Oxygen‐Evolution Reactions

“…Meanwhile, the ECSAs were significantly increased in both the Ni-exsolved CaTiO 3 prepared by solid-state reactions and solvothermal synthesis, but the latter (16.82 cm 2 ) was higher than the former (14.87 cm 2 ) (Figure 2a) (previous metal: >30 cm 2 , transition metal oxides: ≥1 cm 2 , and perovskites: ≈3 cm 2 depending on synthesis methods). [31][32][33] The geometric OER activities were 3.28 mA cm −2 geo , 4.80 mA cm −2 geo , and 10.88 mA cm −2 geo at 1.7 V in the mixture, solid state prepared micrometer scale Ni-exsolved, and Ni-exsolved CaTiO 3 sub-micrometer spheres by solvothermal synthesis, respectively (Figure 2b), which is comparable to state of the art results of both base metals and perovskites (Table S3, Supporting Information). [34,35] The results clearly show that the increase in Adv.…”