Novel Catalyst Synthesis Technique Using Atomic Beam Deposition
Additional Funding Sources
The project described was supported by the Ronald E. McNair Post-Baccalaureate Achievement Program through the U.S. Department of Education under Award No. P217A170273. This work was supported by U.S. Department of Energy (USDOE), Office of Energy Efficiency and Renewable Energy (EERE), Advanced Manufacturing Office Next Generation R&D Projects under Contract No. DE-AC07-05ID14517.
Abstract
A new method for making ultra-sparse deposits of metal onto complex (industrial) catalyst particles is described. Atomic beam deposition (ABD) has been performed on well-defined surfaces, but controlled modification of catalytic particles is more difficult. Actual catalysts are quite complex and their surfaces have many defects. This creates a problem because determining how the surface of a real catalyst controls its kinetic performance is extremely difficult unless real catalytic surfaces can be precisely modified. This connection must be made in order to understand how to make catalysts that are more selective and energy efficient. To allow well defined changes in an existing catalyst particle surface, a new atomic beam deposition tool was designed and constructed. The new deposition system consists of a UHV chamber mounted with an electron beam evaporator and a rotating sample tumbler. As the sample holder rotates, particles tumble in the path of the atomic beam enabling uniform deposition of metal atoms on the catalyst particles. An ultra-sparse (submonolayer) deposit of copper atoms was performed on 250-300 micron silica particles in order to test the precision of this method. This was compared to deposits of iron and copper performed on silica via incipient wetness impregnation.
Novel Catalyst Synthesis Technique Using Atomic Beam Deposition
A new method for making ultra-sparse deposits of metal onto complex (industrial) catalyst particles is described. Atomic beam deposition (ABD) has been performed on well-defined surfaces, but controlled modification of catalytic particles is more difficult. Actual catalysts are quite complex and their surfaces have many defects. This creates a problem because determining how the surface of a real catalyst controls its kinetic performance is extremely difficult unless real catalytic surfaces can be precisely modified. This connection must be made in order to understand how to make catalysts that are more selective and energy efficient. To allow well defined changes in an existing catalyst particle surface, a new atomic beam deposition tool was designed and constructed. The new deposition system consists of a UHV chamber mounted with an electron beam evaporator and a rotating sample tumbler. As the sample holder rotates, particles tumble in the path of the atomic beam enabling uniform deposition of metal atoms on the catalyst particles. An ultra-sparse (submonolayer) deposit of copper atoms was performed on 250-300 micron silica particles in order to test the precision of this method. This was compared to deposits of iron and copper performed on silica via incipient wetness impregnation.
Comments
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