Towards the continuous production of Pt-based heterogeneous catalysts using microfluidic systems

The continuous production of Pt-based heterogeneous catalysts based on ultra-small (<2 nm) noble metal nanoparticles deposited on mesoporous ordered silica and their catalytic activity in VOC abatement are here reported. Microfluidic reactors can be used not only to enable the fast and controlled production of ultra-small Pt nanoparticles (NPs), but also alloyed NPs including PtPd, PtRu and PtRh can be formed in short residence times (between 60 s and 5 min). A novel continuous and homogeneous loading of these catalytic NPs on SBA-15 used as a mesoporous support is also here reported. This procedure eases the NP loading and minimizes washing post-treatments. A 12-fold decrease in the synthesis time was obtained when using this microfluidic reactor compared to the traditional batch production of Pt NPs. Microflow and batch type reactors yielded a Pt precursor conversion to generate Pt NPs with a 90% and 85% yield, respectively. Under the same conditions, the productivity of the microfluidic system (27 mg Pt NPs per h) was twice the one achieved in the conventional batch type reactor. The catalytic performance of the supported catalysts separately prepared by microfluidics and by conventional impregnation under the same conditions and with the same noble metal loading was also compared in the n-hexane abatement as a model of VOCs. Both catalysts were active in the VOC oxidation reaction but a 95% reduction in the catalyst synthesis time was obtained when using the catalysts produced in the microfluidic platform. For this reaction a long-term activity test was successfully carried out at 175 °C during 30 h on stream using the heterogeneous catalyst prepared by using the flow reactor

¿Reportar mediciones o midiendo para reportar? Medición interna de la Economía Circular desde una perspectiva de la contabilidad medioambiental y su interrelación

This paper aims to provide a model to measure the circular economy in businesses from an environmental accounting approach. The range of circular activities and the intensity with which companies implement them are analysed to increase the understanding of the relationship between the implementation of circular economy in firms and their different environmental management accounting and reporting practices. The study is developed through an empirical analysis based on a survey addressed to a sample of Spanish companies and designed to analyse different environmental accounting practices and measure the circular economy-related activities introduced by companies to close the material loops in processes. Main results indicate that circular economy activities are generally introduced by companies progressively, without clearly responding to common patterns for the introduction of the different circular principles and activities. A moderate correlation is observed between companies’ level of circular economy and their environmental management accounting practices, with a more significant correlation for a higher number of circular activities, particularly for firms that implement environmental management systems and have higher levels of transparency and sustainability information policies. Although companies are progressively adopting circular activities, the lack of specific indicators limits their internal measurement. Consequently, the information provided by organisations about the closing of material loops remains sporadic. The results highlight the need for built-in specific metrics to deploy environmental accounting practices in circular economy models.Este trabajo presenta un modelo para medir la economía circular en las empresas desde un enfoque de contabilidad medioambiental. Se analizan tanto el rango de actividades circulares como la intensidad con la que son implementadas para contribuir al conocimiento de la relación entre la introducción de la economía circular en las empresas y sus prácticas de contabilidad e información de gestión medioambiental. El estudio se desarrolla a través de un análisis empírico llevado a cabo a través de una encuesta dirigida a una muestra de empresas españolas diseñada para analizar las prácticas de contabilidad e información medioambiental y de medición de las actividades relacionadas con la economía circular introducidas por las empresas en sus procesos de cierre de círculos de materiales. Los principales resultados obtenidos indican que las actividades de economía circular son generalmente introducidas por las empresas progesivamente, sin responder de forma clara a paulas relacionadas con los distintos principios y actividades circulares. Se observa una correlación moderada entre el nivel de circularidad de las empresas y sus prácticas de contabilidad de gestión medioambiental, siendo la correlación mayor a mayor número de actividades, especialmente en lo que concierne a la implementación de sistemas de gestión ambiental o el desarrollo de políticas de transparencia y de información de sostenibilidad. A pesar de que las empresas estén adoptando progresivamente actividades circulares, la falta de indicadores específicos limita la medición interna de la economía circular por parte de las empresas. Por consiguiente, la información proporcionada por las organizaciones acerca del cierre de círculos sigue siendo esporádica. Los resultados ponen de manifiesto la necesidad de métricas integradas específicas para el despliegue de prácticas de contabildiad medioambiental para modelos de economía circular

Sustainability reporting in view of the European sustainable finance taxonomy: Is the financial sector ready to disclose circular economy?

The European sustainable finance taxonomy requires financial and nonfinancial companies to provide investors with information about the environmental performance of their assets and economic activities. For financial institutions, making socially and environmentally responsible investments visible through a common label that guarantees specific standards for the entire European Union is crucial. Against this background, this study analyzes the evolution of sustainability reporting practices and their assurance in a sample of European financial institutions. To this end, we used a double qualitative methodological approach, based on (a) an external analysis of nonfinancial information and its relationship with the main economic-financial variables of the sample companies, and (b) a case study of a bank carried out through semi-structured interviews. This study provides an external measurement analysis of nonfinancial information in entities from different countries, which can contribute to broadening the scope and level of sustainability and circular economy accountability

Reporting measurements or measuring for reporting? Internal measurement of the Circular Economy from an environmental accounting approach and its relationship

This study presents a model to measure Circular Economy (CE) in businesses from the point of view of both the range of activities and the intensity with which they are implemented to close material circles. The scope of CE is analysed from an environmental accounting approach with the aim of knowing the degree of implementation of the CE and increasing our understanding of the relationship between the implementation of CE in firms and environmental management accounting and reporting practices (EMAR) developed.The results of an empirical survey conducted on a sample of Spanish companies will be used to examine environmental accounting and reporting practices that can be related to the implementation and measurement of CE and also to the progress being made by these companies in closing material and resource circles. The principal results show that CE activities are generally adopted without thinking in an integrated view of CE principles. Furthermore, there is a moderate correlation between the level of circularity of companies and the development of EMAR practices. This correlation is higher the greater the number of EMAR practices that have been developed, especially the implementation of environmental management systems or the development of transparency and reporting policies. Although firms are progressively adopting practices related to CE, the lack of specific indicators does not allow firms to specifically account for their effect on the closing of material loops. Este trabajo presenta un modelo para medir la Economía Circular (CE) en las empresas desde la perspectiva del rango de actividades y de la intensidad con que son implementadas para el cierre de círculos de materiales. El alcance de CE ha sido analizado desde un enfoque de la contabilidad medioambiental con el objetivo de saber el grado de implantación de la CE y aumentar la comprensión de la relación entre la implementación de la CE en las empresas y el desarrollo de prácticas de contabilidad e información de gestión medioambiental (EMAR).Los resultados de una encuesta dirigida a una muestra de empresas españolas han sido utilizados para analizar las prácticas de contabilidad e información medioambiental que pueden estar relacionadas con la implementación y medición de la CE, y con el progreso realizado por dichas compañías en el cierre de círculos de materiales y recursos. Los resultados principales muestran que las actividades de CE son generalmente adoptadas sin tener una visión global e integrada de los principios de la CE. Además, existe una correlación moderada entre el nivel de circularidad de las empresas y el desarrollo de las prácticas EMAR. Esta correlación es mayor cuanto mayor número de actividades de EMAR se han desarrollado, especialmente la implementación de sistemas de gestión ambiental o el desarrollo de políticas de transparencia y de información de sostenibilidad. Las empresas están adoptando progresivamente prácticas que están relacionadas con la CE, pero la falta de indicadores específicos no permite que las empresas contabilicen específicamente su efecto en el cierre de círculos

Efficient and facile tuning of Vulcan XC72 with ultra-small Pt nanoparticles for electrocatalytic applications

In this work, we report the synergic combination of tiny, reproducible, and crystalline platinum nanoparticles with functionalized Vulcan XC72 support for the preparation of efficient electrocatalysts. The morphology and crystallinity of Pt NPs, the amination of carbon support and the Pt loading have been properly evaluated by TEM, STEM, ATR-FTIR, XPS and microwave plasma-atomic emission spectrometry MP-AES. The electrochemical performance of the as prepared powders has been evaluated and compared with the exhibited by commercial Pt-ETEK catalyst with similar Pt-loadings, i.e. 20% wt. The herein described electrocatalyst shows higher dispersion (98.2 m2 gPt-1) of Pt nanoparticles (1.5 ± 0.3 nm in size) and strong metal–support interaction than commercial Pt-ETEK counterpart, highlighting the elevated mass activity for methanol electrooxidation

Practical structure solution with ARCIMBOLDO

ARCIMBOLDO combines the location of small fragments with Phaser and density modification with SHELXE of all possible Phaser solutions. Its uses are explained and illustrated through practical test cases

Candida bracarensis, an emerging yeast involved in human infections

Sir, Invasive candidiasis is an increasingly detected complication in hospitalized adult patients, due to an increase in patients at risk (patients admitted to intensive care units, post-surgical patients, neutropenic and immunosuppressed patients). Non- albicans Candida species have increased in multiple centers and new species are proposed. This is the case of Candida nivariensis and Candida bracarensis that are phylogenetically related with C. glabrata, although with sufficiently genotypically different to justify their assignment as separate species..

Unique crystal structure of a novel surfactant protein from the foam nest of the frog Leptodactylus vastus.

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