Authors: Caudillo-Flores, U; Barba-Nieto, I; Gomez-Cerezo, MN; Martinez-Arias, A; Fernandez-Garcia, M; Kubacka, A

ACS Sustain. Chem. Eng.. vol: 7. page: 2168-0485.
Date: sep-16. 2019.
Doi: 10.1021/acssuschemeng.9b03796.

Hydrogen photoproduction using methanol:water mixtures was essayed with PtRu titania-based materials. All materials contain a high-surface area Nb-doped anatase support. Six bimetallic formulations with Pt:Ru ratios from 4:1 to 1:4 and two (Pt and Ru) monometallic reference samples were utilized. The catalytic response of the materials to three main experimental variables (methanol:water molar ratio, catalyst concentration, and light intensity) was studied through a Box-Benhken factorial design and the calculation of the true quantum efficiency. The optimum activity is achieved using a bimetallic PtRu (2:1) composition, which provides outstanding efficiency under ultraviolet (UV), visible, and sunlight illumination, as well as long-term stability. The interpretation of the activity was performed using characterization results, the outcome of an analysis of charge recombination with photoluminescence spectroscopy and of an in situ infrared study under reaction conditions. This proves that the photophysical and chemical properties of metallic Pt particles in contact with Ru oxidized particles are key to render highly active systems..