Evaluating urban freight transport policies within complex urban environments

Urban Freight Transport (UFT) entails significant advantages for the economic growth of cities, but can also hamper population quality of life, obstructing vehicles and people movements while exacerbating environmental problems. Many initiatives have been engaged by many city administrators in order to efficiently manage UFT, evaluating different policies at a global scale. From the perspective of operators, most works analyze a limited set of policies or only focus on the benefits of companies. In this work, a decisionmaking process is used to evaluate a large set of UFT policies, through different attributes representing the advantages and limitations of each policy over promoter companies and the society. To do so, an ex-ante procedure in five steps is proposed to classify the policies: (1) attributes definition, (2) attributes weighting, (3) policy-attribute assessment, (4) policy ranking, and (5) feasibility threshold satisfaction. The whole process is supported on consultations to 26 experts regarding shop supply and restocking activities within complex urban environments. Results show a classification of the analyzed policies, according to their suitability for implementation ; which could be extended (directly or with small adjustments) to other contexts, given the flexibility of the decision-making procedure developed.Peer ReviewedPostprint (author's final draft

Transient spectroscopic studies of photocatalysts for CO2 and proton reduction

In this thesis, optical and electrochemical techniques are used to study the factors controlling catalytic function in solar-to-fuel conversion systems. Chapter 3, the first results chapter, considers a system for CO2 reduction based on a Re photocatalyst anchored to TiO2. This chapter reports evidence that the immobilisation of the photocatalyst via covalent bonds improves the stability of one of the key reaction intermediates resulting in higher catalytic yields. This chapter also provides insight into the nature and timescale of the steps in the mechanism of CO2 reduction. Chapter 4 considers a proton reduction system based on a Ru absorber, a Ni electrocatalyst and a sacrificial electron donor. This chapter discusses the mechanism behind the strong pH dependence in this system. The results show that whereas the electron transfer between the dye anions and the electrocatalyst is pH independent, the generation of dye anions and the catalytic function of the electrocatalyts have opposite pH-dependencies. Chapter 5 considers a photocathode for proton reduction based on a Cu2O/Al:ZnO buried p-n junction with protection and catalyst layers. The results presented show that the buried junction controls charge separation and the photocurrent onset. Furthermore, the catalyst layer is found to slow down charge recombination and help achieve high reduction yields. This chapter also discuses the mechanism of proton reduction and how the nature of the rate-limiting step has an impact in the recombination kinetics. Chapter 6 discusses the use of transient absorption spectroscopy to study high refractive index materials with high quality interfaces. This chapter investigates light interference effects in TiO2, Cu2O and a CH3NH3PbI3 perovskite device. The results show that interference effects in these materials can dominate their transient spectra, hindering its interpretation. However, it is found that this spectroscopy can also be used to extract information about the changes of the refractive index.Open Acces

Distribución urbana de mercancías: descripción y clasificación de soluciones existentes e implementación de dos soluciones novedosas

En este trabajo se describen y clasifican las soluciones existentes para la distribución urbana de mercancías (DUM) y se proponen dos soluciones novedosas aplicables a la DUM. La descripción de las soluciones proviene de una extensa revisión de la literatura existente. La clasificación de las soluciones existentes es fruto del análisis realizado por los autores, gracias al cual se propone una nueva clasificación en 6 categorías distintas. En cuanto a las soluciones novedosas, se describen y se analiza su utilidad mediante dos pruebas piloto en España en establecimientos de las enseñas Eroski, Caprabo y Mercadona. A lo largo de las pruebas piloto queda patente que dichas dos soluciones pueden ser de gran utilidad para el sector de la DUM

Dye-sensitised semiconductors modified with molecular catalysts for light-driven H2 production.

The development of synthetic systems for the conversion of solar energy into chemical fuels is a research goal that continues to attract growing interest owing to its potential to provide renewable and storable energy in the form of a 'solar fuel'. Dye-sensitised photocatalysis (DSP) with molecular catalysts is a relatively new approach to convert sunlight into a fuel such as H2 and is based on the self-assembly of a molecular dye and electrocatalyst on a semiconductor nanoparticle. DSP systems combine advantages of both homogenous and heterogeneous photocatalysis, with the molecular components providing an excellent platform for tuning activity and understanding performance at defined catalytic sites, whereas the semiconductor bridge ensures favourable multi-electron transfer kinetics between the dye and the fuel-forming electrocatalyst. In this tutorial review, strategies and challenges for the assembly of functional molecular DSP systems and experimental techniques for their evaluation are explained. Current understanding of the factors governing electron transfer across inorganic-molecular interfaces is described and future directions and challenges for this field are outlined.This work was supported by the EPSRC (EP/H00338X/2 to E.R.; DTG scholarship to E.P.), the Christian Doppler Research Association (Austrian Federal Ministry of Science, Research and Economy and National Foundation for Research, Technology and Development; E.R. and J.W.), the OMV Group (E.R. and J.W.), the Advanced Institute for Materials ResearchCambridge Joint Research Centre (K.O.), European Commission Marie Curie CIG (303650 to A.R.) and the ERC (291482 to J.D.).This is the final version of the article. It was first available from RSC via http://dx.doi.org/10.1039/C5CS00733

Improving the photocatalytic reduction of CO2 to CO through immobilisation of a molecular Re catalyst on TiO2.

The photocatalytic activity of phosphonated Re complexes, [Re(2,2'-bipyridine-4,4'-bisphosphonic acid) (CO)3(L)] (ReP; L = 3-picoline or bromide) immobilised on TiO2 nanoparticles is reported. The heterogenised Re catalyst on the semiconductor, ReP-TiO2 hybrid, displays an improvement in CO2 reduction photocatalysis. A high turnover number (TON) of 48 molCO molRe(-1) is observed in DMF with the electron donor triethanolamine at λ>420 nm. ReP-TiO2 compares favourably to previously reported homogeneous systems and is the highest TON reported to date for a CO2-reducing Re photocatalyst under visible light irradiation. Photocatalytic CO2 reduction is even observed with ReP-TiO2 at wavelengths of λ>495 nm. Infrared and X-ray photoelectron spectroscopies confirm that an intact ReP catalyst is present on the TiO2 surface before and during catalysis. Transient absorption spectroscopy suggests that the high activity upon heterogenisation is due to an increase in the lifetime of the immobilised anionic Re intermediate (t50% >1 s for ReP-TiO2 compared with t50% = 60 ms for ReP in solution) and immobilisation might also reduce the formation of inactive Re dimers. This study demonstrates that the activity of a homogeneous photocatalyst can be improved through immobilisation on a metal oxide surface by favourably modifying its photochemical kinetics.Financial support from the EPSRC (EP/H00338X/2 to E.R.; studentship and Doctoral Prize to C.D.W.; DTP scholarship to E.P.), the Christian Doppler Research Association (Austrian Federal Ministry of Science, Research and Economy and the 28 National Foundation for Research, Technology and Development) and the OMV Group (to E.R.), the ERC (project Intersolar to J.D.) and the European Commission Marie Curie CIG (PCIG10-GA-2011-303650 to A.R.) is gratefully acknowledged.This is the final published version. It first appeared in Chemistry - a European Journal, 2015, 21, 3746 – 3754, DOI: 10.1002/chem.20140504

Analysis of urban freight distribution measures

Urban Freight Distribution (UFD) represents a very important activity in terms of cities economy, but can also be a problem for the daily life of citizens, due to traffic, noise and environmental contamination. Therefore UFD activities must be managed cautiously, to avoid or minimise external negative effects. In this context, this research aims to evaluate existing UFD measures, ranking the m from the best to the worst one, according to experts’ opinions. The proposed evaluation process is flexible in order to allow evaluating future UFD measures that may arise.Preprin

Lyon- Madrid freight transport corridor greenness: indicators and actions

Postprint (published version