表面改性
析氧
催化作用
X射线光电子能谱
钴
电化学
化学
无机化学
氧化态
电解质
氧气
化学工程
电极
物理化学
有机化学
工程类
作者
Yasutaka Nagai,Juliana Bruneli Falqueto,Adam H. Clark,Nur Sena Yüzbasi,Thomas Graule,Dominika Baster,Mario El Kazzi,Thomas J. Schmidt,Emiliana Fabbri
标识
DOI:10.1002/sstr.202300106
摘要
Cobalt‐based oxides have attracted attention as active electrocatalysts for the oxygen evolution reaction (OER) in alkaline electrolytes. However, highly OER active catalysts at near‐neutral pHs are also desired for practical applications. Herein, a dry phosphate functionalization process is presented to enhance the OER activity of different cobalt‐based catalysts at near‐neutral pHs. Electrochemical evaluations show that the P‐functionalization can effectively improve the OER activity at near‐neutral pHs for La 0.2 Sr 0.8 CoO 3– δ , La 0.2 Sr 0.8 Co 0.8 Fe 0.2 O 3– δ , and CoO x catalysts, but not for La 0.5 Sr 1.5 CoO 4– δ . Bulk and surface sensitive X‐ray absorption spectroscopy and X‐ray photoelectron spectroscopy unveil the influence of P incorporated in the order of ppm on the electronic state, local structure, and surface composition of the investigated catalysts. The P‐functionalization reduces the Co oxidation state in La 0.2 Sr 0.8 CoO 3– δ and La 0.5 Sr 1.5 CoO 4– δ , but the latter also presents significant Sr‐based segregations on the surface‐inhibiting OER activity at near‐neutral pHs. Differently, La 0.2 Sr 0.8 CoO 3– δ , and to a lesser extent La 0.2 Sr 0.8 Co 0.8 Fe 0.2 O 3–δ and CoO x , shows improved OER activity at neutral pH after the P‐functionalization. The findings disclose that P‐functionalization successfully enhances OER activity at near‐neutral pHs and that both phosphate ion assistance in the OER mechanism and catalyst Co oxidation state can play a role in the enhanced OER activity.
科研通智能强力驱动
Strongly Powered by AbleSci AI