(6ey) Polymer Supported Catalysts for Heterogeneous Catalysis

Selective and efficient conversion of oil or gas feedstock into highly valued bulk and fine chemicals is one of the major focal points in heterogeneous catalysis. Traditional inorganic catalyst supports suffer from mass transfer limitations, coking and low interaction with organic molecules. In particular, catalytic reactions in fine chemical synthesis require a suitable environment of ligands and solvent, which provide the required geometry and stabilize the transition state of the reaction. Polymers create a ‘solvent’-like organic reaction environment, onto which ligands and metal complexes can be grafted, or metal nanoparticles can be loaded to provide the catalytic functionality. Polymers also swell when placed in a solvent enabling new mass transfer pathways. However, most of polymers do not offer high thermal stability and resilience to mechanical stress, which consequently leads to a limited use in industrial reactions. My core competence is to design and synthesize thermally and mechanically stable polymer supports, to introduce functional groups into these polymer supports, to test them in model reactions and to apply them to practically relevant industrial processes.

PI Experience:

In November 2012, I joined Prof. Ferdi Schüth’s group as a postdoc. I discussed the idea of ultrasonic spray pyrolysis as a method to synthesize catalysts with him and he agreed to give me the financial support but I had to find a lab facility to conduct the research. With his help, I was offered laboratory space from Prof. Christof Schulz and Dr. Hartmut Wiggers at the University of Duisburg-Essen. I applied and obtained an Alexander von Humboldt fellowship to add to the financial support given by Ferdi Schüth. After proposing the idea, three PhD students were very eager to join the lab and work with me on this interesting work. Currently, mesoporous sulfonated carbon spheres have been synthesized via one step ultrasonic spray pyrolysis using cheap precursors and will be tested in dehydration reactions.

Research Experience:

My PhD thesis focused on controlled synthesis of colloidal nanoparticles, heterostructures and their applications in catalysis. For instance, plasmonic-catalytic nanostructures have been synthesized to utilize solar energy in heterogeneous catalysis. Entering my postdoc, I broadened my field into the catalyst-support interaction. I have developed a polyphenylene support as an excellent platform for heterogeneously catalyzed reactions, which are normally carried out under homongeneous conditions. High thermal stability of the polyphenylene support further enables gas phase continuous partial oxidation of benzyl alcohol to benzaldehyde. I have also built an in situ electron paramagnetic resonance setup to study the redox properties of CuO-CeO₂. Using this set-up combined with online mass spectroscopy, the three step redox mechanism could be directly observed for the first time.

Teaching Experience:

I have two years’ experience as a teaching assistant in Chemical Principles and three years’ experience as a teaching assistant in Astronomy. I taught the exercise courses and tutorials, off-class activities, and also main lectures. I have also tutored 4 PhD students. Currently, I supervise an exchange student, Jacob Oskar Abildström, from The Technical University of Denmark in our group.

Future Research:

My core competence as a faculty member in chemical engineering department is to design polymer supports for heterogeneous catalysis. In the short term, my research comprises of polymer synthesis, studing their chemical and thermal stability, mass transfer, functionalization, and activity in model reactions. Cross coupling polycondensation, cyclotrimerization, radical or acid/base catalyzed polymerizations are the major routes to obtain conjugated and non-conjugated polymers. Metal nanoparticles are impregnated via swelling-impregnation method developed by myself. In addition, the spray drying technique offers a continuous way to synthesize polymer catalysts. Chemical stability of polymers can be studied by treatment with redox gas or liquids at reaction conditions. Their relations with polymer structure will be investigated by varying the ratio between aromatic and aliphatic units. Selective hydrogenation of alkynes with different molecular sizes will be used to investigate the mass transfer limitation. The polymer supported catalysts will be tested in several model reactions both with loaded metals, ligands or a combination of both. The focus for the application of the reactive polymers will be cross-coupling reaction, selective oxidation and hydrogenation. If selected to obtain tenure, I will aim for more challenging tasks with polymers, such as inorganic-organic hybrid catalysts, gas phase heck reactions, and benzene to phenol conversions.

Selected Publications:

(14 total, 7 first author, 427 total citations, 1 patent – ResearcherID F-6893-2014)

1. Feng Wang, Jerrik Mielby, Felix Herrmann Richter, Guanghui Wang, Gonzalo Prieto, Takeshi Kasama, Claudia Weidenthaler, Hans-Josef Bongard, Søren Kegnæs, Alois Fürstner, Ferdi Schüth “A Polyphenylene Support for Pd Catalysts with Exceptional Catalytic Activity” Angew. Chem. Int. Ed. 2014, DOI: 10.1002/anie.201404912.
2. Feng Wang, Si Cheng, Zhihong Bao, Jianfang Wang “Anisotropic overgrowth of metal heterostructures induced by site-selective silica coating” Angew. Chem. Int. Ed. 2013, 52, 10344-10348.
3. Feng Wang, Chuanhao Li, Huanjun Chen, Ruibin Jiang, Ling-Dong Sun, Quan Li, Jianfang Wang, Jimmy C. Yu, Chun-Hua Yan “Plasmonic harvesting of light energy for Suzuki coupling reactions” J. Am. Chem. Soc. 2013, 135, 5588-5601.
4. Feng Wang, Ling-Dong Sun, Jun Gu, Wei Feng, Yi Yang, Jianfang Wang, Chun-Hua Yan “Selective Heteroepitaxial Nanocrystal Growth of Rare Earth Fluorides on Sodium Chloride: Synthesis and Density Functional Calculations” Angew. Chem. Int. Ed. 2012, 51, 8796-8799.
5. Feng Wang, Chuanhao Li, Ling-Dong Sun, Chun-Hu Xu, Jianfang Wang, Jimmy C. Yu, Chun-Hua Yan “Porous Single-Crystalline Palladium Nanoparticles with High Catalytic Activities” Angew. Chem. Int. Ed. 2012, 51, 4872-4876.
6. Feng Wang, Chuanhao Li, Ling-Dong Sun, Haoshuai Wu, Tian Ming, Jianfang Wang, Jimmy C. Yu, Chun-Hua Yan “Heteroepitaxial Growth of High-Index-Faceted Palladium Nanoshells and Their Catalytic Performance” J. Am. Chem. Soc. 2011, 133, 1106-1111.
7. Feng Wang, Ling-Dong Sun, Wei Feng, Huanjun Chen, Man Hau Yeung, Jianfang Wang, Chun-Hua Yan “Heteroepitaxial Growth of Core–Shell and Core–Multishell Nanocrystals Composed of Palladium and Gold” Small 2010, 6, 2566-2575.