Synthesis, Characterization and Catalytic Studies of Transition Metal Carbide Nanoparticles as Environmental Nanocatalysts
Project Information
| Principal Investigator | S. Ismat Ismat Shah |
| Institution | University of Delaware |
| Project URL | View |
| Relevance to Implications | Substantial |
| Class of Nanomaterial | Engineered Nanomaterials |
| Impact Sector | Environment |
| Broad Research Categories |
Generation, Dispersion, Transformation etc. Characterization |
| NNI identifier |
Funding Information
| Country | USA |
| Anticipated Total Funding | $350,000.00 |
| Annual Funding | $175,000.00 |
| Funding Source | EPA |
| Funding Mechanism | Extramural |
| Funding Sector | Government |
| Start Year | 2002 |
| Anticipated End Year | 2004 |
Abstract/Summary
The future targets for the reductions of emission gases from automobile exhaust are very demanding. For example, the 2004 Ultra Low Emission Vehicle (ULEV) Act requires that the level of NOx must be reduced to 0.05 g/mile, i.e., one quarter of the currently allowed value. The current catalytic converter technology is incapable of achieving such goals without increasing the amount of Pt-group precious metals to levels at which the converters might become prohibitively expensive. The objective of this proposal is to carry out an investigation into the synthesis, characterization and application of nanoparticles of transition metal carbides and oxycarbides as replacement for Pt-group metals (Ru, Rh, Ir, Pd and Pt). The choice of materials is based on recent results that show strong similarities in the catalytic properties between transition metal carbides and the more expensive Pt-group metals. In addition to offering a very high surface/volume ratio, nanoparticles offer the flexibility of tailoring the structure and catalytic properties the on nanometer scale.
Approach:
The proposal blends instrument development, synthesis, characterization and fundamental studies of catalytic processes on transition metal carbide and oxycarbide nanoparticles for exhaust gas treatment. A novel process/instrument will be developed for high rate, controlled synthesis of carbide nanoparticles. A hollow cathode cylindrical magnetron with a split cathode design will be built in order to exploit recent advances in mid-frequency reactive sputtering for this application. Molybdenum (Mo) and Tungsten (W) carbides and oxycarbides in nanoparticle form will be synthesized. We will characterize the physical and electronic properties of the nanoparticles using a synchrotron-based technique, NEXAFS, at Brookhaven National Laboratory (BNL). We will investigate the chemical and catalytic properties towards the decomposition of NO using several surface techniques including Temperature Programmed Desorption (TPD), Auger Electron Spectroscopy (AES) and NEXAFS.
Expected Results:
Based on our preliminary results on the bulk transition metal carbides and oxycarbides, it is expected that the nanoparticles of these compounds will show activities suitable for use in increasingly demanding environmental remediation applications, in particular in the reduction of nitric oxides. Such alternates to the traditional Pt-group catalysts will be extremely economical and will make further reductions in the exhaust gas levels possible in the future.
