Catalytic applications of waste derived materials

Sustainability has become a watchword and guiding principle for modern society, and with it a growing appreciation that anthropogenic 'waste', in all its manifold forms, can offer a valuable source of energy, construction materials, chemicals and high value functional products. In the context of chemical transformations, waste materials not only provide alternative renewable feedstocks, but also a resource from which to create catalysts. Such waste-derived heterogeneous catalysts serve to improve the overall energy and atom-efficiency of existing and novel chemical processes. This review outlines key chemical transformations for which waste-derived heterogeneous catalysts have been developed, spanning biomass conversion to environmental remediation, and their benefits and disadvantages relative to conventional catalytic technologies

Selective electrocatalysis of biofuel molecular oxidation using palladium nanoparticles generated on Shewanella oneidensis

Production of molecular scale palladium (Pd) nanoparticles (NPs) is important due to their catalytic function in electrochemical oxidation of a number of core fuel molecules in fuel cells. Biogenic methods offer an economic and environmentally friendly synthesis route. In this work, the electrochemically active bacterium Shewanella oneidensis MR-1 is employed as a reducing agent to generate PdNPs as well as a support for the immobilization of the PdNPs. The synthesis was carried out at 28 °C and pH 7.0, and completed within one hour. The PdNPs are monodisperse (6.2 nm) and located on the bacterial membrane surface. Mapping by conductive atomic force microscopy shows that the presence of these PdNPs promotes electron transfer and enhances the electric conductivity of the cells. Compared to electrodeposited PdNPs, PdNPs generated by S. oneidensis MR-1 catalyze electrochemically the oxidation of formate with 200 mV less over-potential. Notably they show unique selective activity toward electrochemical oxidation of formate, whereas no electrochemical catalysis was found for oxidation of ethanol, methanol and acetate. This work demonstrates a sustainable and low-cost method for producing efficient PdNP catalysts with high catalytic selectivity

Continuity or Change? Intervention and Statebuilding after Kosovo

The significance of Kosovo can only be understood by first situating the intervention in 1999 and the subsequent statebuilding process in a historical context. While there is a profound difference between 1999 and today, we should not conclude that this means the practice of humanitarian intervention has gone into decline as a result of waning western power. Decisions on intervention at that juncture, as indeed they are today. I conclude by arguing, however, that the theory and practice of statebuilding, has changed markedly since 1999; expectations as to the capacity of international administrations to transform post-conflict societies have declined markedly