Polytechnic University of Valencia

About: Polytechnic University of Valencia is a education organization based out in Valencia, Spain. It is known for research contribution in the topics: Catalysis & Population. The organization has 16282 authors who have published 40162 publications receiving 850234 citations.

Catalysis and photocatalysis by metal organic frameworks

Abstract: Metal organic frameworks (MOFs) are a class of porous crystalline materials that feature a series of unique properties, such as large surface area and porosity, high content of transition metals, and possibility to be designed and modified after synthesis, that make these solids especially suitable as heterogeneous catalysts. The active sites can be coordinatively unsaturated metal ions, substituents at the organic linkers or guest species located inside the pores. The defects on the structure also create these open sites. The present review summarizes the current state of the art in the use of MOFs as solid catalysts according to the type of site, making special emphasis on the more recent strategies to increase the population of these active sites and tuning their activity, either by adapting the synthesis conditions or by post-synthetic modification. This review highlights those reports illustrating the synergy derived from the presence of more than one of these types of sites, leading to activation of a substrate by more than one site or to the simultaneous activation of different substrates by complementary sites. This synergy is frequently the main reason for the higher catalytic activity of MOFs compared to homogeneous catalysts or other alternative solid materials. Besides dark reactions, this review also summarizes the use of MOFs as photocatalysts emphasizing the uniqueness of these materials regarding adaptation of the linkers as light absorbers and metal exchange at the nodes to enhance photoinduced electron transfer, in comparison with conventional inorganic photocatalysts. This versatility and flexibility that is offered by MOFs to optimize their visible light photocatalytic activity explains the current interest in exploiting these materials for novel photocatalytic reactions, including hydrogen evolution and photocatalytic CO2 reduction.

SLEPc: A scalable and flexible toolkit for the solution of eigenvalue problems

Abstract: The Scalable Library for Eigenvalue Problem Computations (SLEPc) is a software library for computing a few eigenvalues and associated eigenvectors of a large sparse matrix or matrix pencil. It has been developed on top of PETSc and enforces the same programming paradigm.The emphasis of the software is on methods and techniques appropriate for problems in which the associated matrices are sparse, for example, those arising after the discretization of partial differential equations. Therefore, most of the methods offered by the library are projection methods such as Arnoldi or Lanczos, or other methods with similar properties. SLEPc provides basic methods as well as more sophisticated algorithms. It also provides built-in support for spectral transformations such as the shift-and-invert technique. SLEPc is a general library in the sense that it covers standard and generalized eigenvalue problems, both Hermitian and non-Hermitian, with either real or complex arithmetic.SLEPc can be easily applied to real world problems. To illustrate this, several case studies arising from real applications are presented and solved with SLEPc with little programming effort. The addressed problems include a matrix-free standard problem, a complex generalized problem, and a singular value decomposition. The implemented codes exhibit good properties regarding flexibility as well as parallel performance.

Optical chemosensors and reagents to detect explosives

Abstract: This critical review is focused on examples reported from 1947 to 2010 related to the design of chromo-fluorogenic chemosensors and reagents for explosives (141 references).