Wang C, Zeng L, Guo W, Gong C, Yang J. Enhancing oxygen and hydrogen evolution activities of perovskite oxide LaCoO3via effective doping of platinum.
RSC Adv 2019;
9:35646-35654. [PMID:
35528107 PMCID:
PMC9074704 DOI:
10.1039/c9ra05491j]
[Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 09/14/2019] [Indexed: 01/20/2023] Open
Abstract
In this study, a series of perovskite oxides LaCo1−xPtxO3−δ (x = 0, 0.02, 0.04, 0.06, and 0.08) were prepared by the citric acid–ethylenediaminetetraacetic acid (CA–EDTA) complexing sol–gel method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Then, the samples were investigated as OER and HER bifunctional electrocatalysts in alkaline media. Compared with other catalysts, LaCo0.94Pt0.06O3−δ had good stability and presented more activity at a lower overpotential of 454 mV (at 10 mA cm−2), a lower Tafel slope value of 86 mV dec−1 and a higher mass activity of 44.4 A g−1 for OER; it displayed a lower overpotential of 294 mV (at −10 mA cm−2), a lower Tafel slope value of 148 mV dec−1 and a higher mass activity of −34.5 A g−1 for HER. The improved performance might depend on a larger ECSA, faster charge transfer rate and higher ratio of the highly oxidative oxygen species (O22−/O−). Furthermore, the eg orbital filling of Co approaching 1.2 in the B site might play a leading role.
Among the perovskite LaCo1−xPtxO3−δ catalysts, LaCo0.94Pt0.06O3−δ proved best for catalyzing OER/HER, with η = 454/294 mV, which might be attributed to LCP6 having the eg orbital filling of Co closest to 1.2.![]()
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