Semiconductor,molecular and hybrid systems for photoelectrochemical solar fuel production

The paper shortly reviews the basic direct approaches applied in searching for viable solutions to solar fuel production. These are generally distinguished in molecular and semiconductor(non-molecular)systems, however, hybrid strategies, proposed recently, have also been included. The most promising efforts are considered, highlighting key aspects and emerging critical issues. Special attention is paid to aspects such as electrode architecture, device design, and main differences in the scientific vision and challenges to directly produce solar fuels. This overview could be useful to orientate the readers in the wide panorama of research activities concerning water splitting, natural and artificial photosynthesis, and solar fuel production through the identification of common aspects, specialties and potentialities of the many initiatives and approaches that are developing worldwide in this field with the final aim to meet world energy demand.

The energy-chemistry nexus: A vision of the future from sustainability perspective

The changing energy-chemistry nexus is discussed in this perspective paper about the future of sustainable energy and chemical production to identify the priorities and open issues on which focus research and development. Topics discussed regard （i） the new sustainable energy scenario, （ii） the role of energy storage （from smart grids to chemical storage of energy）, （iii） the outlooks and role of solar （bio）refineries and solar fuels, （iv） how to integrate hio- and solar-refineries to move to new economy, （v） the role of methanol at the crossover of new energy-chemistry nexus, （vi） the role of chemistry in this new scenario, （vii） the role of nanomaterials for a sustainable energy, （viii） the use of nanocarbons to design advanced energy conversion and storage devices, and （ix） possibilities and routes to exploit solar energy and methane （shale gas）. The contribution provides a glimpse of the emerging directions and routes with some elements about their possible role in the future scenario, but does not orovide a detailed analysis of the state of the art in these directions

A Study on the Thermal Stability of La_2O_3-TiO_2 Supports

In this paper,various techniques including BET,XRD,SEM and XPS were used to study the sintering of pure and La_2O_3-doped titania.The experimental results show that sintering of titania proceeds via volume diffu- sion.Adding of lanthanum oxide decreases the rate of sintering and hinders the phase transition from anatase to rutile crystal by strong surface interaction between the mixed crystals(La_4Ti_9O_(24),La_(0.66)TiO_(2.99))and TiO_2.

The Effect of Platinum on Stability of the B_2O_3/TiO_2-ZrO_2 Catalyst for Beckmann Rearrangement of Cyclohexanone Oxime

The addition of platinum over the B2O3/TiO2-ZrO2 remarkably enhanced its catalytic stability in the vapor phase Beckmann rearrangement of cyclohexanone oxime under the carder gas of H2. The content of coke deposited on catalyst surface was decreased from 1.92% over the B2O3/TiO2-ZrO2 to 1.14% over the platinum promoted B2O3/TiO2-ZrO2 after reaction of six hours. This result indicates that the platinum added on the B2O3/TiO2-ZrO2 catalyst plays an important role in reducing the coke formation on the catalyst surface.

Surface tuning of LaCoO_(3) perovskite by acid etching to enhance its catalytic performance

The stoichiometric LaCoO_(3) and nonstoichiometric LaCo_(1.2)O_(3) perovskite catalysts were prepared by citric acid sol-gel method,and then,LaCoO_(3) perovskite was etched with nitric acid.The structure,surface composition and reducibility of the catalyst were studied by X-ray diffraction(XRD),nitrogen desorption,transmission electron microscope(TEM),temperature program reduction of H_(2)(H_(2)-TPR) and X-ray photoelectron spectroscopy(XPS).It was found that nitric acid etching did not change the crystal structure and the overall morphology of the LaCoO_(3) catalyst,but it can cause the exposure of B-site Co metal to the surface of the catalyst.As a result,after acid etching,the reducibility of the LaCoO_(3) catalyst was improved,leading to the improvement in the catalytic activity of the LaCoO_(3) catalyst for CO oxidation and C_(3)H_(8) combustion.Moreover,the catalytic activity of the LaCoO_(3) catalyst after acid etching was higher than that of LaCo_(1.2)O_(3) and CoOx/LaCoO_(3) catalyst.

Synthesis and characterisation of potassium polytitanate for photocatalytic degradation of crystal violet

Potassium titanate nanostructures were synthesised by hydrothermal treatment of TiO2 （P25） in KOH and H2O2. As-produced powders were characterised by scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, X-ray diffraction, and nitrogen adsorption-desorption methods. Longitudinally-oriented-wire-like structures with a length up to several micrometres and diameters ranging from 10 to 30 nm were obtained. Larger size fibrous nanowires resulting from the hydrotherrnal treatment showed high affinity in adsorbing crystal violet （CV）, which was mainly due to their high surface area. The photocatalytic bleaching of CV solution revealed that the wires are photoactive under ultraviolet light irradiation. Macroporous nanowires are considered as effective adsorbents of CV, capable of photocatalvtic degradation, and they can be easily separated from the solution by settling.

The EXAFS and IR characterization of Rh particles derived from NaY-zeolite entrapped Rh_6(CO)_(16)in CO and H_2 chemisorption

Metal clusters made of neighbouring metal centers with unique structures and stabilizedon a support may provide well-defined heterogeneous catalysts.The idea of constructingthese metal clusters in zeolite cages has been coined as synthesis by a “ship-in-bottle” technique.Here,we report on the structural characterization and chemisorption behavior of NaY zeolite