Nanoparticulate TiO2-promoted PtRu/C catalyst for methanol oxidation

Abstract

To improve the electrocatalytic properties of PtRu/C in methanol electrooxidation, nanoparticulate TiO 2 -promoted PtRu/C catalysts were prepared by directly mixing TiO 2 nanoparticles with PtRu/C. Using cyclic voltammetry, it was found that the addition of 10 wt% TiO 2 nanoparticles can effectively improve the electrocatalytic activity and stability of the catalyst during methanol electro-oxidation. The value of the apparent activation energy (E a ) for TiO 2 -PtRu/C was lower than that for pure PtRu/C at a potential range from 0.45 to 0.60 V. A synergistic effect between PtRu and TiO 2 nanoparticles is likely to facilitate the removal of CO-like intermediates from the surface of PtRu catalyst and reduce the poisoning of the PtRu catalysts during methanol electrooxidation. Therefore, we conclude that the direct introduction of TiO 2 nanoparticles into PtRu/ C catalysts offers an improved facile method to enhance the electrocatalytic performance of PtRu/C catalyst in methanol electrooxidation. IntroductionCarbon-supported PtRu catalyst, PtRu/C, offers a state-of-the-art anode electrocatalyst for direct methanol fuel cells (DMFCs) due to its high activity toward methanol electrooxidation and tolerance to carbon monoxide poisoning [1][2][3][4][5]. Alloying Pt with Ru promotes the formation of oxygenated species at a lower temperature than Pt particles and promotes oxidation of CO to CO 2 . However, despite promising progress in the development of PtRu/C, the durability and activity of the PtRu/C anode still cannot meet the demands for practical DMFCs applications.

Characterization and performance evaluation of Pt Ru/C TiO2 anode electrocatalyst for DMFC applications

“…This can be associated with the improved electrocatalytic properties of PteRu/CeTiO 2 anode electrocatalyst containing 5 wt.% of commercial TiO 2 ; hence, TiO 2 nanoparticles facilitates the conversion of CO into CO 2 . As previously mentioned in Section Effect of weight ratio of TiO 2 , this facilitation in the conversion of CO into CO 2 mitigates the electrocatalyst poisoning phenomenon and improves the stability of the anode electrocatalyst towards the MOR [36] excessive amount of TiO 2 might also obstruct the adsorption of CH 3 OH, leading to a significant drop in the power density.…”

“…The decrease in the performances could be associated with the fact that excessive amount of TiO 2 may prevent the transportation of the electrons to the PteRu anode electrocatalyst by creating an additional barrier between the electrons and PteRu. As previously mentioned, the additional OH species, which are originated from the presence of TiO 2 , may also obstruct the adsorption of CH 3 OH by occupying the active areas [36].…”

“…The results of the conducted studies revealed that mixing TiO 2 materials with PteRu/C could improve the electrocatalytic properties of PteRu/C, especially for methanol electrooxidation. For instance, Wang et al [36] prepared TiO 2 À promoted PteRu/C anode electrocatalysts adding TiO 2 nanoparticles directly to PteRu/C and investigated electrocatalytic activity and stability properties of the anode electrocatalyst in the MOR through cyclic voltammetry. Their study results clearly demonstrated that the introduction of TiO 2 materials into PteRu/C anode electrocatalyst provides an improved electrocatalytic performance during the MOR.…”

Fe–Co hybrid oxides promoted Pd electrocatalysts with enhanced catalytic performance for ethylene glycol oxidation

“…Fig. 2d shows the linear sweep voltammograms (LSV) curves in 0.1 M KOH þ 0.5 M EG at a scan rate of 1 mV s À1 , which is close to a steady-state polarization curve of the EGOR and reflects kinetic processes in some degree [29]. In low potentials (<À0.3 V), the current of all catalysts increases slowly with the increase of polarization potential.…”

The effect of hydrothermal treatment time and level of carbon coating on the performance of PtRu/C catalysts in a direct methanol fuel cell

“…A variety of carbon-based materials, 8 such as carbon nanotubes (CNT), [9][10][11][12] carbon nanobers (CNF), 13 or graphene, [14][15][16] as well as non-carbonaceous based materials, including titania, 17,18 indium oxides, 19 silica, 20 tungsten oxide, 21-23 manganese dioxide 24 or graphitic carbon nitride (g-C 3 N 4 ) [25][26][27] are attractive candidates for the catalyst support. A variety of carbon-based materials, 8 such as carbon nanotubes (CNT), [9][10][11][12] carbon nanobers (CNF), 13 or graphene, [14][15][16] as well as non-carbonaceous based materials, including titania, 17,18 indium oxides, 19 silica, 20 tungsten oxide, 21-23 manganese dioxide 24 or graphitic carbon nitride (g-C 3 N 4 ) [25][26][27] are attractive candidates for the catalyst support.…”