Solar Light Induced Photon-Assisted Synthesis of TiO2 Supported Highly Dispersed Ru Nanoparticle Catalysts

Abstract

Ru/TiO2 are promising heterogeneous catalysts in different key-reactions taking place in the catalytic conversion of biomass towards fuel additives, biofuels, or biochemicals. TiO2 supported highly dispersed nanometric-size metallic Ru catalysts were prepared at room temperature via a solar light induced photon-assisted one-step synthesis in liquid phase, far smaller Ru nanoparticles with sharper size distribution being synthesized when compared to the catalysts that were prepared by impregnation with thermal reduction in hydrogen. The underlying strategy is based on the redox photoactivity of the TiO2 semi-conductor support under solar light for allowing the reduction of metal ions pre-adsorbed at the host surface by photogenerated electrons from the conduction band of the semi-conductor in order to get a fine control in terms of size distribution and dispersion, with no need of chemical reductant, final thermal treatment, or external hydrogen. Whether acetylacetonate or chloride was used as precursor, 0.6 nm sub-nanometric metallic Ru particles were synthesized on TiO2 with a sharp size distribution at a low loading of 0.5 wt.%. Using the chloride precursor was necessary for preparing Ru/TiO2 catalysts with a 0.8 nm sub-nanometric mean particle size at 5 wt.% loading, achieved in basic conditions for benefitting from the enhanced adsorption between the positively-charged chloro-complexes and the negatively-charged TiO2 surface. Remarkably, within the 0.5–5 wt.% range, the Ru content had only a slight influence on the sub-nanometric particle size distribution, thanks to the implementation of suitable photo-assisted synthesis conditions. We demonstrated further that a fine control of the metal Ru nanoparticle size on the TiO2 support was possible via a controlled nanocluster growth under irradiation, while the nanoparticles revealed a good resistance to thermal sintering.

TiO2 supported Ru catalysts for the hydrogenation of succinic acid: influence of the support

“…Furthermore, in the case of the Anatase-P support, a Ru/TiO2 catalyst was prepared via a solar light-photoassisted synthesis method using Ru(acac)3 as precursor as described in the literature 18,19 . It involved the controlled irradiation with simulated solar light for 3 h of a water-methanol TiO2 suspension in the presence of the Ru precursor, by taking advantage of the solar light-induced properties developed by the TiO2 surface for reducing the Ru precursor adsorbed at the support surface into metallic Ru.…”

Ruthenium on Alkali‐Exfoliated Ti3(Al0.8Sn0.2)C2 MAX Phase Catalyses Reduction of 4‐Nitroaniline with Ammonia Borane

“…However, these signals can be extracted using a similar approach as with Ru 3d and C 1s. Ru 3p are much broader than Ti 2p and there are no Ru signals below 461 eV [88–91] . This means that the Ti 2p signals up to 459 eV can be quantitatively assigned.…”

Electron Coupling between the Linear-Conjugated Polymer Nanocluster and TiO2 Nanoparticle Enables a Quantum Leap for Visible Light-Driven Hydrogen Evolution

“…Whereas, for bare TiO 2 , a weight loss of 1.39% (Figure 1) infers the removal of crystallization water. 39 By considering the above scenarios, as compared to that of bare TiO 2 , the weight loss of PF3T@TiO 2 is increased by ∼0.984 wt %. By taking the formation of Pd oxide into account, the content of the PF3T is 1.013 wt % in PF3T@TiO 2 .…”