457913 Fundamental Studies and Applications of Nano-Structured Catalysts in Domestic Fuel Production

Sunday, November 13, 2016
Continental 4 & 5 (Hilton San Francisco Union Square)
Cun Wen, Chemical Engineering, University of South Carolina, Columbia, SC

Fundamental studies and Applications of Nano-structured Catalysts in Domestic Fuel Production

Cun Wen, University of South Carolina, Columbia, SC

Liquid fuels are the largest commodity on the market in terms of total volume of sales, but the U.S. is lagging behind the curve of novel technologies for domestic fuel production and upgrading. For instance, U.S. is projected to be a fuel exporting country in the next few years because of the booming of shale gas. However, exporting shale gas has the lowest market value per energy content. Upgrading shale gas into gasoline, on the other side, can boost the price by more than 230%. Unfortunately, this technology is yet to appear on the horizon for the U.S. shale-gas producer, while South Africa and China have already built and operated such units for decades. Besides civilian fuel production, the situation of military fuel generation is not optimistic either. U.S. still can’t fly a High-hypersonic jet with speed exceeding Mach 10, while other countries have already tested their high-hypersonic vehicles for several years. Lagging behind in powering high-hypersonic jet will potentially expose our homeland to other country’s high speed jets and missiles, and therefore is a serious national-security concern. One of the main problems for powering high-hypersonic jet is to provide high energy-density fuels to the engine. Another example of domestic fuel production is the biofuels. In 2013, the US Navy and Airforce were still paying more than $15 dollars/gallon for biofuels. The high production cost was a result of energy-intensive processes that were needed at the time. Domestic production of transportation fuel is one of the United States’ top priorities, as underscored by President Obama in his 2012 State of the Union Address: “This country needs an all-out, all-of-the-above strategy that develops every available source of American energy…… and nowhere is the promise of innovation greater than in American-made energy.”

To produce fuel domestically, catalyst development resides in the heart of the solution, because a good catalyst can lead to fuels with higher through-put, lower price, and higher energy-density. Herein, my group will be focused on developing novel catalysts for domestic fuel production and upgrading. Through my enriched experience in energy catalysis, I have studied reactions involved in almost every aspect of domestic fuel production, such as methane partial oxidation, water gas shift, Fischer-Tropsch, and hydrodeoxygenation for biodiesel production.1-11 One uniqueness in my problem-solving technique is design catalyst’s nanostructure based on fundamental understanding of reaction mechanism and kinetics. A recent example of how I apply such strategy to solve long-standing problems is designing the first-of-its-kind self-healing catalysts for Fischer-Tropsch synthesis. Cobalt catalysts have been considered the most attractive catalyst among all candidate metals, but a bottle-neck issue with cobalt catalysts is their tendency to deactivation through oxidation by water produced during the process. Through a comprehensive study of the reaction mechanism and kinetics, my idea is to design a cobalt catalyst that can be easily reduced with hydrogen in the feedstock so that the oxidation/deactivation process can be reversed. This idea, in the end, led to the first self-healing catalysts and attracted great amount of interests from academia and industry.11,12 On the other hand, instead of solely relying on fundamental understanding in literature, my group will interrogate the reaction of interest with a unique approach of combining spectroscopic and kinetic studies. Often people study either reaction mechanism or kinetic one at a time. However, reaction mechanism is the reaction pathway that has the highest reaction rate among all routes. Therefore, a combination of spectroscopic and kinetic studies can lead to more comprehensive understanding of the reaction, and this approach has led to our new understanding in century-old reactions, such as methane partial-oxidation.1,8,10 With my strength in catalyst design and fundamental understanding, breakthroughs in domestic fuel production and upgrading are expected to benefit our society and prosperity.

Research Interests: Catalysis, nanomaterial, renewable energy

Teaching Interests: thermos, kinetics

Read Me More:

1.              Wen C, Liu Y, Guo Y, Wang Y, Lu G. Strategy to eliminate catalyst hot-spots in the partial oxidation of methane: enhancing its activity for direct hydrogen production by reducing the reactivity of lattice oxygen. Chem Commun. 2010;46(6):880-882.

2.              Wen C, Dunbar D, Zhang X, Lauterbach J, Hattrick-Simpers J. Self-healing catalysts: Co3O4 nanorods for Fischer-Tropsch synthesis. Chem Commun. 2014;50:4575-4578.

3.              Wen C, Zhu Y, Ye Y, et al. Water–Gas Shift Reaction on Metal Nanoclusters Encapsulated in Mesoporous Ceria Studied with Ambient-Pressure X-ray Photoelectron Spectroscopy. ACS Nano. 2012;6:9305–9313.

4.              Wen C, Liu Y, Tao F. Integration of surface science, nanoscience, and catalysis. Pure Appl Chem. Jan 2011;83(1):243-252.

5.              Liu Y, Wen C, Guo Y, Lu G, Wang Y. Modulated CO Oxidation Activity of M-Doped Ceria (M = Cu, Ti, Zr, and Tb): Role of the Pauling Electronegativity of M. J Phys Chem C. 2010;114(21):9889-9897.

6.              Liu Y, Wen C, Guo Y, Lu G, Wang Y. Effects of surface area and oxygen vacancies on ceria in CO oxidation: Differences and relationships. J Mol Catal a-Chem. Feb 2010;316(1-2):59-64.

7.              Liu Y, Wen C, Guo Y, et al. Mechanism of CO Disproportionation on Reduced Ceria. ChemCatChem. 2010;2(3):336-341.

8.              Pichon A. Catalysis: Lower reactivity means more hydrogen. 2010; http://www.nature.com/nchina/2010/100120/full/nchina.2010.7.html.

9.              Saxton C. Enhancing catalytic activity. 2010; http://www.rsc.org/Publishing/ChemTech/Volume/2010/02/enhancing_catalytic.asp.

10.           Chinese New Year. Chem Commun. 2010.

11.           Jacoby M. Custom Catalyst Resists Oxidation. C&EN News. 2014;92(13):25.

12.           Catalysts C. Self-healing F-T catalysts. 2014; http://www.caicatalysts.com/news-a-links/news/69-self-healing-f-t-catalysts.

 


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