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

The multicomponent complex Pt/TiO2-CNx catalysts with different TiO2 anatase/rutile phases synthesized by ethylene glycol reduction were investigated. Herein, FESEM, TEM, BET, XANES, EXAFS, XPS, CV and RDE techniques are adopted to systematically investigate the relationship between composition, structure and performance of catalysts with ultrafine Pt nanoparticles, CNx nanowires and TiO2 co-catalyst. Firstly, we discussed the correlation between HOR electrocatalytic activity and ultrafine Pt nanoparticles in the range of 1.8-2.8 nm. The HOR electrocatalytic activity increases with decreasing of Pt nanoparticles size, showing a positive nanoparticle size effect on HOR. Furthermore, the HOR activity of Pt/TiO2-CNx are affected by the content of TiO2 anatase/rutile phases, showing a volcano-type curve, and Pt/TiO2(25 %R)-CNx containing 25% rutile has the highest HOR electrocatalytic activity with kinetic current density of 16.801 mA cm(-2) and exchange current density of 0.962 mA cm(-2). It also revealed a strong metal-support interaction (SMSI) between Pt nanoparticles and TiO2-CNx support resulting from the electrons drift from TiO2-CNx to Pt promotes the HOR electrocatalytic activity of the Pt/TiO2-CNx catalyst. Our results explain to some extent the dependence among Pt nanoparticles, CNx nanowires and TiO2 co-catalyst, as well as the scientific problem between the size of Pt nanoparticles and HOR electrocatalytic & nbsp; activity.

Automated summary

The study investigates the performance of composite Pt/TiO2-CNx catalysts with different TiO2 anatase/rutile phases synthesized by ethylene glycol reduction. Results show that the size of Pt nanoparticles significantly affects HOR activity, and the activity of Pt/TiO2-CNx catalysts is influenced by the TiO2 phase content.