能源化学(英文版)

能源化学(英文) ›› 2019, Vol. 28 ›› Issue (7): 227-239.DOI: 10.1016/j.jechem.2019.03.008

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Supporting IrO2 and IrRuOx nanoparticles on TiO2 and Nb-doped TiO2 nanotubes as electrocatalysts for the oxygen evolution reaction

Radostina V. Genova-Kolevab, Francisco Alcaidea, Garbiñe Álvareza, Pere L. Cabotb, Hans-Jürgen Grandea, María V. Martínez-Huertac, Oscar Miguela   

  1. a CIDETEC, P° Miramón, 196, 20014 San Sebastián, Spain;
    b Laboratory of Electrochemistry of Materials and the Environment, Department of Materials Science and Physical Chemistry, Universitat de Barcelona, Martí i Franqués 1-11, 08028 Barcelona, Spain;
    c Instituto de Catálisis y Petroleoquímica, CSIC, C/Marie Curie, 2, 28049 Madrid, Spain
  • 收稿日期:2019-01-15 修回日期:2019-03-04 出版日期:2019-07-15 发布日期:2019-07-15
  • 通讯作者: Francisco Alcaide
  • 基金资助:
    The authors would like to thank to EU FP7 SUSHGEN Network project No. 238678 and project ENE2017-83976-C2-1-R (AEI/FEDER, EU)).

Supporting IrO2 and IrRuOx nanoparticles on TiO2 and Nb-doped TiO2 nanotubes as electrocatalysts for the oxygen evolution reaction

Radostina V. Genova-Kolevab, Francisco Alcaidea, Garbiñe Álvareza, Pere L. Cabotb, Hans-Jürgen Grandea, María V. Martínez-Huertac, Oscar Miguela   

  1. a CIDETEC, P° Miramón, 196, 20014 San Sebastián, Spain;
    b Laboratory of Electrochemistry of Materials and the Environment, Department of Materials Science and Physical Chemistry, Universitat de Barcelona, Martí i Franqués 1-11, 08028 Barcelona, Spain;
    c Instituto de Catálisis y Petroleoquímica, CSIC, C/Marie Curie, 2, 28049 Madrid, Spain
  • Received:2019-01-15 Revised:2019-03-04 Online:2019-07-15 Published:2019-07-15
  • Contact: Francisco Alcaide
  • Supported by:
    The authors would like to thank to EU FP7 SUSHGEN Network project No. 238678 and project ENE2017-83976-C2-1-R (AEI/FEDER, EU)).

摘要： IrO2 and IrRuOx (Ir:Ru 60:40 at%), supported by 50 wt% onto titania nanotubes (TNTs) and (3 at% Nb) Nb-doped titania nanotubes (Nb-TNTs), as electrocatalysts for the oxygen evolution reaction (OER), were synthesized and characterized by means of structural, surface analytical and electrochemical techniques. Nb doping of titania significantly increased the surface area of the support from 145 (TNTs) to 260 m2 g-1 (Nb-TNTs), which was significantly higher than those of the Nb-doped titania supports previously reported in the literature. The surface analytical techniques showed good dispersion of the catalysts onto the supports. The X-ray photoelectron spectroscopy analyses showed that Nb was mainly in the form of Nb(IV) species, the suitable form to behave as a donor introducing free electrons to the conduction band of titania. The redox transitions of the cyclic voltammograms, in agreement with the XPS results, were found to be reversible. Despite the supported materials presented bigger crystallite sizes than the unsupported ones, the total number of active sites of the former was also higher due to their better catalyst dispersion. Considering the outer and the total charges of the cyclic voltammograms in the range 0.1-1.4 V, stability and electrode potentials at given current densities, the preferred catalyst was IrO2 supported on the Nb-TNTs. The electrode potentials corresponding to given current densities were between the smallest ones given in the literature despite the small oxide loading used in this work and its Nb doping, thus making the Nb-TNTs-supported IrO2 catalyst a promising candidate for the OER. The good dispersion of IrO2, high specific surface area of the Nb-doped supports, accessibility of the electroactive centers, increased stability due to Nb doping and electron donor properties of the Nb(IV) oxide species were considered the main reasons for its good performance.

关键词: Nb-doped TiO2 nanotubes, IrO2 catalyst, IrRuOx catalyst, Oxygen evolution reaction, PEMWE

Abstract: IrO2 and IrRuOx (Ir:Ru 60:40 at%), supported by 50 wt% onto titania nanotubes (TNTs) and (3 at% Nb) Nb-doped titania nanotubes (Nb-TNTs), as electrocatalysts for the oxygen evolution reaction (OER), were synthesized and characterized by means of structural, surface analytical and electrochemical techniques. Nb doping of titania significantly increased the surface area of the support from 145 (TNTs) to 260 m2 g-1 (Nb-TNTs), which was significantly higher than those of the Nb-doped titania supports previously reported in the literature. The surface analytical techniques showed good dispersion of the catalysts onto the supports. The X-ray photoelectron spectroscopy analyses showed that Nb was mainly in the form of Nb(IV) species, the suitable form to behave as a donor introducing free electrons to the conduction band of titania. The redox transitions of the cyclic voltammograms, in agreement with the XPS results, were found to be reversible. Despite the supported materials presented bigger crystallite sizes than the unsupported ones, the total number of active sites of the former was also higher due to their better catalyst dispersion. Considering the outer and the total charges of the cyclic voltammograms in the range 0.1-1.4 V, stability and electrode potentials at given current densities, the preferred catalyst was IrO2 supported on the Nb-TNTs. The electrode potentials corresponding to given current densities were between the smallest ones given in the literature despite the small oxide loading used in this work and its Nb doping, thus making the Nb-TNTs-supported IrO2 catalyst a promising candidate for the OER. The good dispersion of IrO2, high specific surface area of the Nb-doped supports, accessibility of the electroactive centers, increased stability due to Nb doping and electron donor properties of the Nb(IV) oxide species were considered the main reasons for its good performance.

Key words: Nb-doped TiO2 nanotubes, IrO2 catalyst, IrRuOx catalyst, Oxygen evolution reaction, PEMWE