REU Final Presentation August 1 st, 2013 Analysis of the Promoter-Catalyst interaction between Mn and Rh by Transmission Electron Microscopy Ben Graham Department of Materials Science and Engineering, University of Alabama at Birmingham Robert Klie, PhD Department of Physics, University of Illinois at Chicago

REU Final Presentation August 1 st, 2013 Introduction An alternative source of energy is a major concern for society. Draw Backs for traditional fermentation routes include: Slow conversion process Inefficient conversion process By-products (such as ammonia) the Fischer-Tropsch mechanism can convert syngas(or bio-gas) to higher octane fuels such as ethanol. It is possible to increase the activity and selectivity of the mechanism by adding a catalyst and promoter. Catalyst of interest is Rhodium promoted by Manganese

REU Final Presentation August 1 st, 2013 Introduction SEA strategy for increased promoter- metal interactions catalysts EELS mapping of SEA promoted catalyst Electron Energy Loss Spectroscopy (EELS) collects the inelastically- scattered electrons to determine chemical bonding. J.R. Regalbuto, Catalyst Preparation: Science and Engineering, Taylor & Francis/CRC Press, Boca Raton, 2006, pp Sample was prepared in previous study

REU Final Presentation August 1 st, 2013 Introduction J. Liu and et al, Selective Absorption of Manganese onto Rhodium for optimized Mn/Rh/SiO 2 Alcohol Synthesis Catalysts. print

REU Final Presentation August 1 st, 2013 TEM JEM 3010, basic TEM was used Transmitted elastically scattered electrons can be assembled into bright field images (composed of phase and mass contrast) D.B. Williams, C.B. Carter, Transmission Electron Microscopy. 1996, New York, Springer Science,7-141.

REU Final Presentation August 1 st, 2013 TEM D.B. Williams, C.B. Carter, Transmission Electron Microscopy. 1996, New York, Springer Science,

REU Final Presentation August 1 st, 2013 TEM Images 3% Rh/CNT sample at 600Kx, atomic resolution of particles 3% Rh/CNT sample at 300Kx, ideal for particle sampling

REU Final Presentation August 1 st, 2013 TEM Images 2% Mn/3%Rh/CNT sample at 600Kx, atomic resolution of particles 2% Mn/3%Rh/CNT sample at 300Kx, ideal for particle sampling 1.96 nm total 9 fringes 0.22 nm each (111) orientation Emaps.mrl.uiuc.edu

REU Final Presentation August 1 st, 2013 Particle Size Measurements Average particle size for 3%Rh/CNT: 1.9 ± 0.6 nm Average Particle Size for 1%Mn/3%Rh/CNT 2.1 ± 0.5nm 3% Rh/CNT 1%Mn/3%Rh/CNT Average Particle Size (nm) Count

REU Final Presentation August 1 st, 2013 Particle Size Measurements Average particle size for 2% Mn/3%Rh/CNT: 3.2 ± 0.6 nm Distribution for all samples were Gaussian or normal. Catalyst Average Particle Size (nm) Standard Deviation (±nm) 3% Rh/CNT % Mn/3% Rh/CNT % Mn/3% Rh/CNT %Mn/3%Rh/CNT Average Particle Size (nm) Count

REU Final Presentation August 1 st, 2013 Particle Orientation 3.57nm 16 Fringes nm each In (111) plane Catalyst Coordination Number (EXAFS)* Bond Distance (Å) (EXAFS)* Experimental Lattice Parameter (Å) (TEM) 3% Rh/CNT ±0.1 1% Mn/3% Rh/CNT ±0.1 2% Mn/3% Rh/CNT ±0.1 a= Lattice parameter d= measured d-spacing (hkl)= corresponding miller indices J. Liu and et al, Selective Absorption of Manganese onto Rhodium for optimized Mn/Rh/SiO 2 Alcohol Synthesis Catalysts. print %Mn/3%Rh/CNT image at 600k

REU Final Presentation August 1 st, 2013 Discussion CatalystSTEM* size (nm) 3%Rh/CNT1.3 ±0.4 1%Mn/3%Rh/CNT1.1±0.4 2%Mn/3%Rh/CNT1.2 ±0.4 STEM Dark Field Image of 2%Mn/3%Rh/CNTs (left) STEM Dark field image composed of Z- contrast TEM bright field image composed of phase and mass contrast TEM Catalyst Average Particle Size (nm) Standard Deviation (±nm) 3% Rh/CNT % Mn/3% Rh/CNT % Mn/3% Rh/CNT Rh Mn J. Liu and et al, Selective Absorption of Manganese onto Rhodium for optimized Mn/Rh/SiO 2 Alcohol Synthesis Catalysts. print

REU Final Presentation August 1 st, 2013 Conclusions & Future Work n Determined nano- particle size for promoted and un- promoted rhodium on carbon nano-tubes n Found evidence of manganese-rhodium interactions Increase in particle size Decrease in lattice parameter n Examine Rh particles on a Mn substrate n Electron Diffraction analysis of samples

REU Final Presentation August 1 st, 2013 Acknowledgments n NSF grant – EEC-NSF Grant # n Nanoscale Physics Group n Research Recourses Center East staff n Dr. Takoudis, Dr. Jursich, and REU Staff Thank You! Questions?