Nanoparticle size effect of Pt and TiO2 anatase/rutile phases “volcano-type” curve for HOR electrocatalytic activity at Pt/TiO2-CNx nanocatalysts

Hydrogenated TiO2 Carbon Support for PtRu Anode Catalyst in High‐Performance Anion‐Exchange Membrane Fuel Cells

“…The SMSI imparted by metal-oxides in general are found to alter the electronic structure of both Pt and Ru metals which optimizes the HBE and OHBE toward improvement of the HOR activity. [6,7,31,56] It is worth noting that, in the case of PtRu/TiO 2 /C-400, the relative at% of metallic Pt (53.4%) and Ru (68.2%) were higher than the metallic Pt (50.6%) and Ru (64.0%) sites in commercial PtRu/C. Such a higher number of metallic active sites is also beneficial for the adsorption of surface species, such as H ads and OH ads , for efficient HOR on PtRu/TiO 2 /C-400.…”

“…For example, Pt or Pd deposited on various oxophilic transition metal-oxide supports, such as CeO 2 , RuO 2 , TiO 2 , SnO 2 , and ZrO 2 , have exhibited enhanced HOR activity owing to the strong metal-support interaction (SMSI) and better control of the size of the catalyst NPs. [25,[28][29][30][31][32][33][34] The SMSI between precious metals and transition metal-oxide supports leads to the weakening of the HBE on metal surfaces due to the modification of the electronic structure of the metal. [6,7] In addition, it also helps in the facile removal of hydrogen intermediates due to the improved oxophilicity (OH − spillover capacities) imparted by metal-oxides.…”

“…[35][36][37] However, due to the poor electronic conductivity of pristine TiO 2 (wide band gap of ≈3.2 eV), it needs to be either doped or formed as hybrids with carbon nanostructures, which have been studied as effective supports for electrochemical reactions such as methanol oxidation and CO oxidation. [31,38] Elezovic et al developed a TiO x -covered Pt/C catalyst by polyol synthesis resulting in enhanced HOR activity with an exchange current density j 0 of 0.4 mA cm −2 Pt , which was twice that of the Pt/C counterpart without TiO x . [39] Cui et al explored the effect of different phases of TiO 2 deposited on carbon nitride (CN x ) in controlling NP size and SMSI between Pt and TiO 2 to enhance the HOR activity of Pt.…”

“…[39] Cui et al explored the effect of different phases of TiO 2 deposited on carbon nitride (CN x ) in controlling NP size and SMSI between Pt and TiO 2 to enhance the HOR activity of Pt. [31] Geppart et al reported the SMSI effect of Pt deposited via atomic layer deposition onto TiO 2−Y toward HOR and other electrochemical reactions in an acidic medium. They showed a good control of the particle size due to SMSI and indicated efficient hydrogen and proton transport through the thin TiO x film while bulkier oxygenated species were unable to transport through the thin film of TiO x .…”

“…[ 35–37 ] However, due to the poor electronic conductivity of pristine TiO 2 (wide band gap of ≈3.2 eV), it needs to be either doped or formed as hybrids with carbon nanostructures, which have been studied as effective supports for electrochemical reactions such as methanol oxidation and CO oxidation. [ 31,38 ]…”