Design of hybrid asymmetric capacitors in aqueous electrolyte using ZTC and ultraporous activated carbons

The use of two different materials as electrodes allows the construction of asymmetric and hybrid capacitors cells with enhanced energy and power density. This approach is especially well-suited for overcoming the limitations of pseudocapacitive materials that provide a huge capacitance boost, but in a limited potential window. In this work, we introduce the concepts and protocols that are required for a successful design of such systems, which is illustrated by the construction of an asymmetric hybrid cell where a zeolite-templated carbon and an ultraporous activated carbon have been combined.

Electrochemical Characterization of Shape-Controlled Pt Nanoparticles in Different Supporting Electrolytes

The voltammetric profile of preferentially shaped platinum nanoparticles has been used to analyze the different sites present on the surface. For the first time, this analysis has been made in NaOH solutions and revisited in sulfuric and perchloric acid media. The comparison with the voltammetric profiles of the model surfaces, that is, single-crystal electrodes, allows assigning the different signals appearing in the voltammograms of the nanoparticle to specific sites on the surface. A good correlation between the shape of the nanoparticle determined by TEM and the voltammetric profile is obtained. For the nanoparticles characterized in alkaline media, the adsorbed species on the surface have been characterized, and three major regions can be identified. Below 0.2 V, the major contribution is due to hydrogen adsorption, whereas above 0.6 V, adsorbed OH is the main species on the surface. Between those values, the signals are due to the competitive adsorption/desorption process of OH/H. New criteria for determining the active area in NaOH solutions has been proposed. In this medium, the total charge density measured between 0.06 and 0.90 V stands for 390 μC cm–2. The areas measured are in perfect agreement with those measured in acid media. Once the nanoparticles have been characterized, the behavior of the nanoparticles toward CO oxidation is analyzed and compared with that observed for single-crystal electrodes.

Performance Assessment of a Polymer Electrolyte Membrane Electrochemical Reactor under Alkaline Conditions – A Case Study with the Electrooxidation of Alcohols

A novel polymer electrolyte membrane electrochemical reactor (PEMER) configuration has been employed for the direct electrooxidation of propargyl alcohol (PGA), a model primary alcohol, towards its carboxylic acid derivatives in alkaline medium. The PEMER configuration comprised of an anode and cathode based on nanoparticulate Ni and Pt electrocatalysts, respectively, supported on carbonaceous substrates. The electrooxidation of PGA was performed in 1.0 M NaOH, where a cathode based on a gas diffusion electrode was manufactured for the reduction of oxygen in alkaline conditions. The performance of a novel alkaline anion-exchange membrane based on Chitosan (CS) and Poly(vinyl) alcohol (PVA) in a 50:50 composition ratio doped with a 5 wt.% of poly (4-vinylpyridine) organic ionomer cross-linked, methyl chloride quaternary salt resin (4VP) was assessed as solid polymer electrolyte. The influence of 4VP anionic ionomer loading of 7, 12 and 20 wt.% incorporated into the electrocatalytic layers was examined by SEM and cyclic voltammetry (CV) upon the optimisation of the electroactive area, the mechanical stability and cohesion of the catalytic ink onto the carbonaceous substrate for both electrodes. The performance of the 4VP/CS:PVA membrane was compared with the commercial alkaline anion-exchange membrane FAA −a membrane generally used in direct alcohol alkaline fuel cells- in terms of polarisation plots in alkaline conditions. Furthermore, preparative electrolyses of the electrooxidation of PGA was performed under alkaline conditions of 1 M NaOH at constant current density of 20 mA cm−2 using a PEMER configuration to provide proof of the principle of the feasibility of the electrooxidation of other alcohols in alkaline media. PGA conversion to Z isomers of 3-(2-propynoxy)-2-propenoic acid (Z-PPA) was circa 0.77, with average current efficiency of 0.32. Alkaline stability of the membranes within the PEMER configuration was finally evaluated after the electrooxidation of PGA.

In sickness and in health: protecting and supporting public investment in Europe. Bruegel Policy Contribution 2014/02, February 2014

The long-term decline in gross public investment in European Union countries mirrors the trend in other advanced economies, but recent developments have been different: public investment has increased elsewhere, but in the EU it has declined and even collapsed in the most vulnerable countries, exaggerating the output fall. The provisions in the EU fiscal framework to support public investment are very weak.The recently inserted ‘investment clause’ is almost no help. In the short term, exclusion of national co-funding of EU-supported investments from the fiscal indicators considered in the Stability and Growth Pact would be sensible. In the medium term, the EU fiscal framework should be extended with an asymmetric ‘golden rule’ to further protect public investment in bad times, while limiting adverse incentives in good times. During a downturn, a European investment programme is needed and the European Semester should encourage greater investment by member states with healthy public finances and low public investment rates. Reform and harmonisation of budgeting, accounting, transparency and project assessment is also needed to improve the quality of public investment.

Supporting Access to Finance by SMEs: Mapping the initiatives in five EU countries. ECMI Research Report No. 9, April 2014

This paper maps the initiatives to support access to finance for small- and medium-sized enterprises (SMEs) that were available at national level in 2012 in the five biggest European economies (Germany, France, the UK, Italy and Spain). This mapping distinguishes initiatives promoted and financed primarily through public resources from those developed independently by the market. A second breakdown is proposed for those sources of finance with different targets, i.e. whether the target is debt financing (typically bank loans at favourable conditions, public guarantees on loans, etc.) or equity financing (typically venture capital funds, tax incentives on equity investments, etc.). A broad set of initiatives has been implemented to close the funding gap of SMEs in these five countries. The total amount of public spending for SMEs, however, has remained well below 1% of GDP. Public subsidisation of bank loans has been by far the most diffused type of intervention. Despite the fact that this strategy might prove to be effective in the short term, it fails to address long-term sustainability issues via a more diversified set of financing tools.