Novel nanostructured catalysts for the high-temperature electro-oxidation of small organic molecules

• Applicant: Professor Dr. Rolf Jürgen Behm
• Subject Area: Physical Chemistry of Solids and Surfaces, Material Characterisation
• Term: from 2010 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 164152250

We aim at an in-depth understanding of i) the structure-reactivity correlation in platinum metal (Pt, Pd, ...) nanoparticles, using nanoparticles with well defined and variable shape and facet orientation, and of ii) the surface composition of shape-defined bimetallic nanoparticles in the oxidation of small organic molecules (formic acid, methanol, ethanol …). In addition to understanding the molecular scale reaction mechanism on nanoparticles of well defined morphology and structure, and the effect of surface structure and composition, we are particularly interested in effects caused by the reaction conditions (concentration, temperatures), covering a wide range of reaction conditions, up to fuel cell relevant reaction and transport conditions. Based on the resulting mechanistic understanding, we aim at a systematic improvement of the catalytic behavior of these nanoparticle catalysts in the oxidation of small organic molecules. Furthermore, we will elucidate the stability of the pre-shaped nanoparticles with respect to shape relaxation and sintering, which will be crucial for applications.These objectives shall be reached using preferentially oriented nanoparticles with diameters in the 5-10 nm range and different shapes, whose size and shape will be varied in a controlled way. Synthesis of the nanoparticles and its further systematic improvement is an important part of the project. Variations in the nanoparticle shape correspond to changes in the surface structure, due to the facet specific surface structure. The mechanistic interpretation will largely be based on combined electrochemical and in-situ spectroscopic measurements (Differential Electrochemical Mass Spectrometry (DEMS) and ATR-FTIR), which are performed under up to fuel cell relevant reaction conditions. They provide detailed information on the nature and role of adsorbed and volatile reaction intermediates and reaction side products. Furthermore, we will make use of existing experimental and theoretical data and mechanistic proposals for the respective reactions, and of results in collaborating theory groups.

• DFG Programme: Research Grants
• International Connection: Spain
• Participating Person: Professor Dr. Juan M. Feliu