Centro de Investigación y Desarrollo Tecnológico en Electroquímica

About: Centro de Investigación y Desarrollo Tecnológico en Electroquímica is a based out in . It is known for research contribution in the topics: Cyclic voltammetry & Catalysis. The organization has 537 authors who have published 682 publications receiving 10382 citations. The organization is also known as: Centro de Investigacion y Desarrollo Tecnologico en Electroquimica & Center of Research and Technologic Development in Electrochemistry.

Formic acid microfluidic fuel cell based on well-defined Pd nanocubes

Abstract: Microfluidic fuel cells (μFFC) are emerging as a promising solution for small-scale power demands. The T-shaped architecture of the μFFC promotes a laminar flow regimen between the catholyte and anolyte streams excluding the use of a membrane, this property allows a simplest design and the use of several micromachining techniques based on a lab-on-chip technologies. This work presents a combination of new materials and low cost fabrication processes to develop a light, small, flexible and environmental friendly device able to supply the energy demand of some portable devices. Well-defined and homogeneous Pd nanocubes which exhibited the (100) preferential crystallographic plane were supported on Vulcan carbon and used as anodic electrocatalyst in a novel and compact design of a SU-8 μFFC feeded with formic acid as fuel. The SU-8 photoresist properties and the organic microelectronic technology were important factors to reduce the dimensions of the μFFC structure. The results obtained from polarization and power density curves exhibited the highest power density (8.3 mW cm−2) reported in literature for direct formic acid μFFCs.

Synthesis and evaluation of HfO2 as a prospective filler in inorganic-organic hybrid membranes based on Nafion for PEM fuel cells.

Abstract: Hybrid inorganic-organic Nafion membranes modified with metal oxides (typically TiO2, ZrO2, WO3) are a good alternative for fuel cell applications. However, one of their main limitations is associated with their relative low proton conductivity at temperatures above 80 °C. In this work, we overcome this issue using HfO2 as a filler. HfO2 was prepared by a sol-gel method, and it was compared with a recast Nafion membrane (named as recast). Deconvolved XPS spectra confirmed the presence of hafnia, while EDS analysis was used to determine its weight content resulting in a 1.88 wt%. FT-IR ATR experiments indicated that the HfO2 hybrid membrane possess a higher capability to retain water than the recast. Thus, the water uptake, swelling degree, conductivity tests and fuel cell evaluations were performed. The water uptake analysis revealed that the hybrid membrane presented a higher retention percentage at 100 °C (61%) than recast (29%). This improvement enabled a higher ionic conductivity at 80 °C and 100 °C. The hybrid membrane displayed a higher conductivity at 100 °C than the recast membrane (112 versus 82 mS cm-1), increasing the cell performance to 0.36 W cm-2; being this performance almost two-fold higher to that obtained for the recast membrane. In summary, herein we demonstrated that HfO2 can be considered as an excellent substitute to conventional fillers.

Zn Electrodeposition from an Acidic Chloride Bath Containing Polyethyleneglycol (Mw 200) and Benzylideneacetone as Additives

Abstract: The influence of Polyethylene Glycol 200 (PEG200) or a PEG200/benzylideneacetone (BDA) mixture on the mechanism of Zn deposition and nucleation kinetics was studied by voltammetry, chronoamperometry and atomic force microscopy (AFM). The addition of PEG200 or PEG200/BDA to the solution partially inhibited the reduction of Zn(II) at E ¼� 1.135 V vs. SCE. In the presence of PEG200/BDA, an additional reduction process was observed at E ¼� 1.24 V vs. SCE. Analysis of the nucleation processes indicated that, in all systems studied, the initial stage of Zn deposition was dominated by 3D diffusion-controlled nucleation. At E ¼� 1.132 V vs. SCE, the addition of PEG200 caused a reduction in the nucleation rate constant (A) and the number density of active sites (N0) with respect to the values obtained without additives. AFM analysis of coatings obtained at E ¼� 1.132 V vs. SCE, showed the formation of Zn clusters with different sizes distributed randomly on the surface. At E ¼� 1.243 V vs. SCE, both A and N0were higher for the solution containing the PEG200/BDA mixture than for the systems with PEG200 alone or without additives. AFM analysis revealed the formation of similarly sized Zn clusters uniformly distributed on the surface.