Showing papers by "Marcos Fernández-García published in 2023"
TL;DR: In this paper , a three-level three-factor Box-Behnken design based on the response surface methodology (RSM) was used to determine the effects of parameters including pH, initial dye concentration, and photocatalyst dosage on the photocatalytic degradation of methylene blue (MB) dye.
1 citations
TL;DR: In this article , a series of catalysts with growing quantities of Niobium were prepared using Pd as co-catalyst and a high surface area titania support, showing a constant Pd particle size of ca. 4.6 nm.
1 citations
TL;DR: In this article , the authors introduced some experimental evidence indicating that subsurface Pd hydride species are governing the reactivity of this reaction, and the extent of formation/decomposition of PdHx species is very sensitive to the Pd nanoparticle aggregate dimensions, and this finally controls the selectivity in this process.
Abstract: Structure-sensitive catalyzed reactions can be influenced by a number of parameters. So far, it has been established that the formation of Pd-C species is responsible for the behavior of Pd nanoparticles employed as catalysts in a butadiene partial hydrogenation reaction. In this study, we introduce some experimental evidence indicating that subsurface Pd hydride species are governing the reactivity of this reaction. In particular, we detect that the extent of formation/decomposition of PdHx species is very sensitive to the Pd nanoparticle aggregate dimensions, and this finally controls the selectivity in this process. The main and direct methodology applied to determine this reaction mechanism step is time-resolved high-energy X-ray diffraction (HEXRD).
TL;DR: The role of a Pd-based co-catalyst supported on a high surface area anatase powder is analyzed for the photo-production of hydrogen from methanol:water mixtures in this article .
TL;DR: In this article , the impact of adding zirconium oxide to titanium oxide-supported gold systems on photocatalytic hydrogen production was analyzed, and the results showed a quantum efficiency close to 1.9% under sunlight, which represents a substantial improvement over two orders of magnitude compared to the original titanium system.
TL;DR: In this article, a series of Pd-promoted Nb-doped titania samples were essayed in the gas-phase thermo-photo production of syngas from methanol/water mixtures.
Abstract: In this contribution, a series of Pd-promoted Nb-doped titania samples were essayed in the gas-phase thermo-photo production of syngas from methanol/water mixtures. The Pd loading was tested in the 0.1 to 2.5 wt % range, leading to the presence of metallic nanoparticles under reaction. Reaction rates exceeding 52 mmol H2 g–1 h–1 and quantum efficiencies above 33% were obtained. The optimum sample having a 0.5 wt % of Pd provided an outstanding synergy between light and heat under reaction conditions, facilitating the boost of activity with respect to the single-source processes and achieving high selectivity to syngas. The spectroscopic analysis of the physico-chemical ground of the activity unveiled that the noble metal interaction with the Nb-doped anatase support triggers a cooperative effect, promoting the evolution of formic acid-type methanol-derived carbon-containing species and rendering a significant enhancement of syngas production. The proposed thermo-photo system is thus a firm candidate to contribute to the new green circular economy.