文章信息/Info

Title:

MxCo3-xO4 Mixed with ZnO as an Excellent Electrocatalyst for the Oxygen Evolution Reaction

文章編號(hào):

1674-3962(2020)03-0200-06

作者:

王偉強(qiáng); 姚露露; 顧佳俊

（上海交通大學(xué) 金屬基復(fù)合材料國(guó)家重點(diǎn)實(shí)驗(yàn)室，上海 200240）

Author(s):

WANG Weiqiang; YAO Lulu; GU Jiajun

(The State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, China)

關(guān)鍵詞:

電催化劑; 析氧反應(yīng); MxCo3-xO4; 氧化鋅; 電化學(xué)惰性材料

Keywords:

electrocatalyst;  oxygen evolution reaction;  MxCo3-xO4;  zinc oxide;  electrochemically inactive materials

分類號(hào):

O643.36;TB383.1

DOI:

10.7502/j.issn.1674-3962.201910005

文獻(xiàn)標(biāo)志碼:

A

摘要:

氫能因熱值高、燃燒產(chǎn)物無(wú)污染等優(yōu)良特性，成為目前新型能源研究的焦點(diǎn)，有望成為化石能源的理想替代品。電催化水分解作為最具前景的氫氣制備方法，包含兩個(gè)半反應(yīng)：析氧反應(yīng)（OER）和析氫反應(yīng)（HER）。其中OER目前主要采用貴金屬作為催化劑，但其高成本極大地限制了電催化產(chǎn)氫的工業(yè)化。基于Co3O4的Co基摻雜氧化物具有成本低廉、催化活性高且穩(wěn)定性強(qiáng)等優(yōu)良特性。目前對(duì)于Co基摻雜氧化物的研究主要集中于探究摻雜不同金屬元素（Zn，Ni，F(xiàn)e等）對(duì)其催化活性的影響，極少研究摻雜惰性氧化物對(duì)其催化活性的影響。合成了一種CoFeNiZn復(fù)合氧化物，且具有優(yōu)良的電催化活性和穩(wěn)定性。在1 mol/L KOH的電解液中，10 mA/cm2的電流密度下，CoFeNiZn復(fù)合氧化物過電勢(shì)（η10）為310 mV，塔菲爾斜率（Tafel slope）為40 mV/dec，相比原始CoFeNi氧化物（η10為400 mV）過電勢(shì)降低了90 mV。CoFeNiZn催化劑催化性能的提高主要是由于以惰性ZnO作為基質(zhì)可有效地分散催化活性物質(zhì)，并充分暴露CoFeNi氧化物的催化活性位點(diǎn)。這一基于催化材料摻雜非活性物質(zhì)提高催化劑催化活性的發(fā)現(xiàn)可以為現(xiàn)有催化劑開發(fā)提供新的思路。

Abstract:

Hydrogen, with high calorific value and environmental friendliness, is expected to become a potential alternative energy to replace exhaustible fossil fuels. Electrochemical water splitting is the most promising method to generate hydrogen, which is composed of two half-reactions: oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). However, conventional catalysts for OER are mainly based on precious metals, whose high cost interrupts the further practical applications in HER. In contrast, Co3O4-based oxides doped with transition metals have advantages of low cost, high catalytic activity and strong stability. But the researches of Co-based oxides mainly focus on the effect of doping transition metals (such as Zn, Ni and Fe) on catalytic performance, few of them explore the influence of electrochemically inactive materials. In this paper, a new CoFeNi oxide mixed with ZnO is synthetized. This CoFeNiZn oxide has a superior performance with small Tafel slope (40 mV/dec) and long-term stability. In 1 mol/L KOH electrolyte, the overpotential of the CoFeNiZn oxide is as low as 310 mV at the current density of 10 mA/cm2, which is 90 mV lower than the overpotential of original CoFeNi oxide. The electrochemically inactive ZnO is the critical factor for this remarkable improvement, which can effectively disperse the active materials and fully expose the active sites of CoFeNi oxide. This discovery provides a strategy to design novel catalysts structures for improving electrochemical performance.