We report on the optimization of both the support and the active phase in PdPt NPs supported on TiO2 nanowires to obtain highly active electro/photocatalysts towards the oxygen reduction reaction (ORR) and photocatalytic water splitting. This system displayed strong metal-support interactions, high concentration of oxygen vacancies, and ~2 nm PdPt NPs sizes. By optimizing the loading of PdPt at the TiO2 surface, both photo/electrocatalytic activities were improved compared to commercial materials. Interestingly, a volcano plot between the catalytic activity and the PdPt composition was observed, in which the Pd0.22 Pt0.78-TiO2/C sample led to the optimal performances. For instance, the amount of hydrogen produced from water splitting was 11.6 mmol/gcatalyst. For the ORR, catalytic activity similar to the commercial Pt catalyst but with a lower Eonset (0.87 VRHE vs w 0.95 VRHE) was detected. The variations in the catalytic activities with the composition correlated well with variations in the electronic effects and concentration of oxygen vacancy sites at the catalyst surfaces.

Mono and bimetallic catalysts based on Pt and Pd were prepared by a co-precipitation method. They were tested in liquid phase hydrogenation reactions of glucose and furfural at low temperature and pressure. The bimetallic PtPd/TiO2 catalyst proved to be an efficient material in selectively hydrogenating glucose to sorbitol. Moreover, high furfural conversion was attained under relatively soft conditions, and the furfuryl alcohol selectivity was strongly affected by the chemical composition of the catalysts. Furfuryl alcohol (FA) was the major product in most cases, along with side products such as methylfuran (MF), furan, and traces of tetrahydrofuran (THF). These results showed that the PtPd bimetallic sample was more active relative to the monometallic counterparts. A correlation between the catalytic results and the physicochemical properties of the supported nanoparticles identified key factors responsible for the synergetic behavior of the PtPd system. The high activity and selectivity were due to the formation of ultra-small particles, alloy formation, and the Pt-rich surface composition of the bimetallic particles supported on the TiO2 nanowires.