Due to the large surface area of MCM-41 and the large pore diameter and pore volume of SBA-15, they’re expected to improve the activity of the catalysts.

Converting Syngas to Ethanol With Mesoporous MaterialsJulia Fisher1, Nathalia Backeljauw2

Ephraim Sheerin2, Dr. Panagiotis Smirniotis2, Dr. Krishna Reddy2

1Arizona State University, 2University of Cincinnati

Corn versus Syngas

Problems with Corn as a Source for Ethanol• Centralized in the Midwest• Expensive to produce corn• Food source Advantages of Syngas as a Source for Ethanol• Can be derived from a multitude of sources• No geographic limitations• Would not conflict with food demands

Approach

This project approaches the production of ethanol differently by changing the method and using sources other than corn. In this method, ethanol is produced from the reaction of syngas (carbon monoxide and hydrogen) on Rh-based catalysts supported by mesoporous materials.  

CO + H2 C2H5OH + by-products Supports Synthesized

To increase the activity of the catalysts, Rhodium was impregnated on the supports. All of the supports used in this experiment were mesoporous materials, which have pores from 2-50 nanometers in size. • SBA-15• MCM-41• MCM-48 

 Wet Impregnation

Wet impregnation is the spreading of a catalyst on a support by mixing the two in water. We used this method to impregnate Rhodium on the supports.

• Mix catalyst and support in water• Stir at 100°C until liquids evaporate• Dry for 12 hours at 100°C on stirring plate• Calcine at 400°C for 4 hours

The activity results show that under these conditions, the Rh/SBA-15 has the best qualities for syngas to ethanol conversion, when compared with Rh/MCM-41 and Rh/MCM-48. It had the highest CO conversion, 32%, and the highest ethanol selectivity, 12%. This may be due to the large pore diameter and pore volume of SBA-15.

NSF Grant # DUE-0756921 for Type 1 Science, Technology, Engineering, and Mathematics Talent Expansion Program  (STEP) Project

Special thanks to Dr. Panagiotis Smirniotis, Ephraim Sheerin, and Dr. Krishna Reddy.

Introduction 3

Procedure

Acknowledgements

Synthesized catalysts

A support (MCM-41) in Teflon bottle

Schematic

References3Somma, D., Lobkowicz, H., Deason, J.P. (2010). “Growing America’s fuel: an analysis of corn and cellulosic ethanol feasibility in the United States.” Clean Technologies and Environmental Policy, ASCE, Vol. 12, No. 4, pp. 373-380.

4Sun B., Reddy E. P., Smirniotis, P. G. (2006). “TiO2-loaded Cr-modified molecular sieves for 4-chlorophenol photodegradation under visible light.” Journal of Catalysis, ASCE, Vol. 237, pp. 314-321.

Mesoporous Materials

BETSurface area (m2/g)

Pore volume(cm3/g)

Pore diameter(Å)

Unit cell parameter(Å)

MCM-41 1143 1.03 35 43

MCM-48 983 0.65 26 89

SBA-15 827 1.21 57 117

BET Results 4

The TPR results show that the Rhodium in the samples was in the 3+ oxidation state. At 330°C, all of the Rhodium converted to the 0 oxidation state.

Graph courtesy of Dr. Reddy

TPR Results

Catalyst

CO conversion (%)

Selectivity (%)

Ethanol

Methanol

Methane

CO2

Rh/SBA-15

 32

 12

 8.4

 32.3

 44.5

Rh/MCM-41

 30

 6.4

 5.9

 42.3

 52.4

Rh/MCM-48

 28

 5.8

 6.2

 40.5

 51.4

Table courtesy of Ephraim Sheerin

This table shows the percentages of CO conversion and selectivity of the three catalysts. As shown, Rh/SBA-15 has the highest percentages for CO conversion and ethanol selectivity, making it the most favorable.

Activity Results

Conclusion