Piotr Olszewski

The carbon footprint of a product (CFP) approach is one of the most important tools which gives a possibility to estimate the total amount of greenhouse gas (GHG) emissions in the whole life cycle of consumer goods. A lot of attempts have been undertaken to elaborate methodology for CFP calculation. Because GHG emissions may occur at each stage of the life cycle, the calculation procedures are characterised by a high level of complexity. This is due to the use of a broad range of different materials in the case of the whole footwear manufacturing process. Owing to this fact, a lot of wastes, sewages and toxic gases may be generated at every step of the production process. For each kind of material used, a lot of determinants should be laid down, such as the source of the material as well as distances and means of transportation between manufacturers and consignees. It causes that estimation of total carbon footprint values is not possible, especially in the case of a long and multi-stage supply chain. With the use of the SimaPro LCA software package, the authors calculated the carbon footprint for seven types of outdoor footwear. The CFP was calculated for each step of the life cycle. Based on the calculations, the correlation dependences were revealed and stages with huge emissivity indicated. Then, with the use of a multivariate regression model, the regression function, which determines the total emissivity at each stage, was estimated. This approach gives qualitative indicators which can be taken into account in making decisions about corrective actions.

The electrocatalytic activity of Pt3Ru2/C nanocatalyst toward the electro-oxidation of bulk CO was examined in acid and alkaline solution at ambient temperature using the thin-film, rotating disk electrode (RDE) method. The catalyst was characterized by XRD analysis. The XRD pattern revealed that the Pt3Ru2/C catalyst consisted of two structures, i.e., Pt-Ru-fcc and Ruhcp (a solid solution of Ru in Pt and a small amount of Ru or a solid solution of Pt in Ru). Electrocatalytic activities were measured by applying potentiodynamic and steady state techniques. The oxidation of CO on the Pt3Ru2/C catalyst was influenced by pH and anions from the supporting electrolytes. The Pt3Ru2/C was more active in alkaline than in acid solution, as well as in perchloric than in sulfuric acid. Comparison of CO oxidation on Pt3Ru2/C and Pt/C revealed that the Pt3Ru2/C was more active than Pt/C in acid solution, while both catalysts had a similar activity in alkaline solution.

Electrodes, assigned as GC/Pt-C and GC/Pt-Ru-C, were formed by deposition of Ptbased catalysts (47.5 wt % Pt + high surface area carbon) and (54 wt. % Pt-Ru alloy + high surface area carbon) on glassy carbon (GC) discs. X-ray diffraction measurements were used for the determination of the average crystallite size and phase composition of both catalysts. Crystallite size for Pt-C catalyst was 2.9 nm for Pt-fcc. In the diffraction pattern of the Pt-Ru-C catalyst two phases, e.g. Pt-Ru-fcc and Ru-hcp were refined using the Rietveld method. Crystallite sizes were 3.9 nm for Pt-Ru-fcc and 2.8 nm for Ru-hcp. STM observations of the surface of GC/Pt-C and GC/Pt-Ru-C electrodes revealed the presence of metal particles of the size in the range 2-6 nm and Pt-C or Pt- Ru-C agglomerates in the range of several tenth of nm. The thickness of the Nafion covering layer determined by AFM is ca. 100 nm. A simplified scheme of the investigated electrodes was created.