A study of formaldehyde formation during methanol oxidation over PtRu bulk alloys and nanometer scale catalyst

Electrocatalysis and photoelectrochemistry based on functional nanomaterials

Catalysis plays a key role in chemical production, energy processing, air purification, water treatment, food processing, and the life sciences. Nanostructured materials with high surface areas and some unique properties have received widespread interest in electrocatalysis and photocatalysis. Recently, the author’s research team has designed and studied a variety of novel functional nanomaterials. This review article is derived from the author’s 2013 Canadian Catalysis Lectureship Award Lecture and focuses primarily on the electrocatalytic activities of platinum- and palladium-based nanomaterials and the development of TiO2-based nanostructured photocatalysts. Palladium possesses several exceptional properties that may enable promising applications in hydrogen detection, purification, and storage. The significant roles of palladium-based nanomaterials in facilitating the growth of a hydrogen economy are addressed. As platinum-based catalysts are vital to the development of fuel cells and sensors, the design of high-performance platinum-based electrocatalysts is highlighted. Additionally, TiO2 is considered to be one of the most promising photocatalysts due to its nontoxicity, high stability, and cost effectiveness. The modification of TiO2 nanomaterials to achieve visible light response is discussed as well. It is anticipated that the development of advanced functional nanostructured catalysts will further improve the efficiency and reduce the cost of electrochemical and photochemical processes, making them more attractive in addressing the pressing global energy and environmental issues.

The use of nanoparticles in electroanalysis: an updated review

The use of nanoparticles in electroanalysis is an area of research which is continually expanding. A wealth of research is available discussing the synthesis, characterization and application of nanoparticles. The unique properties of nanoparticulate materials (e.g. enhanced mass transport, high surface area, improved signal-to-noise ratio) can often be advantageous in electroanalytical techniques. The aim of this paper is to provide an updated overview of the work in this field. In this review we have concentrated on the advances with regards to silver, gold, platinum, palladium, ruthenium, copper and nickel. The synthesis, characterization and practical application of these materials are discussed. We have also identified the conditions under which each metal is likely to be stable, which is likely to be a useful tool for those practising in the field. Furthermore, we have provided a theoretical overview of advances in the theoretical modelling and simulation of nanoparticle behaviour.

Transport effects in the electrooxidation of methanol studied on nanostructured Pt/glassy carbon electrodes

Transport effects in the methanol oxidation reaction (MOR) were investigated using nanostructured Pt/glassy carbon (GC) electrodes and, for comparison, a polycrystalline Pt electrode. The nanostructured Pt/GC electrodes, consisting of a regular array of catalytically active cylindrical Pt nanostructures with 55 +/- 10 nm in diameter and different densities supported on a planar GC substrate, were fabricated employing hole-mask colloidal lithography (HCL). The MOR measurements were performed under controlled transport conditions in a thin-layer flow cell interfaced to a differential electrochemical mass spectrometry (DEMS) setup. The measurements reveal a distinct variation in the MOR activity and selectivity (product distribution) with Pt nanostructure density and with electrolyte flow rate, showing an increasing overall activity, reflected by a higher Faradaic reaction current, as well as a pronounced increase of the turnover frequency for CO(2) formation and of the CO(2) current efficiency with decreasing flow rate and increasing Pt coverage. These findings are discussed in terms of the "desorption-readsorption-reaction" model introduced recently (Seidel et al. Faraday Discuss. 2008, 140, 67). Finally, consequences for applications in direct methanol fuel cells are outlined.

How green are the chemicals used as liquid fuels in direct liquid-feed fuel cells?

How green are the chemicals used as liquid fuels in the direct liquid-feed fuel cells intended to mobile, portable applications? Is there any risk of using such fuels? The present paper tries to give indications of answer to these questions while tackling the green chemistry concept, the liquid fuels (i.e. anodic oxidation, inherent hazards and renewability), the reaction products and by-products. The discussion especially focuses on green chemists' critical remarks and the green chemistry principles. Globally none of the liquid fuels appears to be green in terms of toxicity even if most could be produced from renewable raw materials. However this does not necessarily mean that the direct liquid-feed fuel cell technology is not green. The greenness of the direct liquid-feed fuel cell will also depend on its reliability and safety.