Associate Professor Stephan, JAENICKE



B.Sc. (Vordiplom), University of Cologne, 1973; Dr rer. nat., University of Karlsruhe, 1981.

Contact Information

Office: S5-04-06
Tel: (65)-6516-2918 | Fax: (65)-6779-1691
Email: chmsj@nus.edu.sg


 

ORCID: 0000-0002-0149-110X

 

Research Interests

The Jaenicke Research Group conducts studies in heterogeneous catalysis with the aim to understand the origins of catalytic activity, and to use that fundamental understanding for the design of improved catalysts. Reactions are followed by steady state measurements in flow reactors, and by determining the concentration profiles in batch reactions. With these data, the chemical kinetic are determined and the catalytic performance evaluated. We also use spectroscopic measurements to identify species on the catalyst surfaces. X-Ray photoelectron spectroscopy, solid state NMR, UV-vis reflectance and infrared spectroscopy reveal further details of the chemical state of the surface and the bonding of adsorbed species. The acid catalysis by zeolites, hydrodeoxygenation of biomass derived molecules, and the photochemical degradation of recalcitrant organic pollutants over semiconductor surfaces are catalytic systems of current interest. Particularly the conversion of sugars and other biomaterial into platform molecules for the chemical economy of the future, which will be based on renewable raw materials (bio-refinery concept), is central to our research program.

 

Research Highlight

Single-crystalline nanosheets with either {001} or {110} planes as the dominant facets were formed by tuning the pH during synthesis. The {001}-facetted BiOI consisted of large crystallites with low surface areas in contrast to the thinner and smaller {110}-facetted platelets. The specific activity per m2 for the photodegradation of p-cresol was ~ 5 times higher over the {001} than over the {110}-facetted BiOI of p-cresol. The specific activity per m2 for the photodegradation of p-cresol was ~ 5 times higher over the {001} than over the {110}-facetted BiOI which can be correlated to the stronger adsorption of the substrate at the oxygen-rich {001} surface. However, the low surface area of < 1 m2 g-1 is a drawback for practical use. Instead, by simple calcination of {110}-facetted BiOI at structures were formed. Instead, by simple calcination of {110}-facetted BiOI at 350 oC, composites of different BixOyIz phases with closely related crystalline structures were formed. The intimate contact between the phases results in the formation of heterojunctions which greatly improve the photoactivity, even over that of {001}-facetted BiOI.

 

Teaching Contributions 

  • CM3201 Principles of Chemical Processes
  • CM4228 Catalysis

 

Representative Publications   

  • Han, A. J.; Sun, J. L.; Chuah, G. K.; Jaenicke, S, Enhanced p-Cresol Photodegradation over BiOBr/Bi2O3 in the Presence of Rhodamine B. RSC Adv. 2017, 7, 145–152.
  • Roslan, I. I.; Ng, K.-H.; Chuah, G. K.; Jaenicke, S. 2-Aminopyridines as an a-Bromination Shuttle in a Transition Metal-Free One-Pot Synthesis of Imidazo[1,2-a]pyridines. Adv. Synth. Catal. 2016, 358, 364-369.
  • Liu, H.; Chuah, G. K.; Jaenicke, S. Alumina-Entrapped Ag Catalyzed Nitro Compounds Coupled with Alcohols using Borrowing Hydrogen Methodology. Phys. Chem. Chem. Phys. 2015, 17, 15012-15018.
  • Han, A. J.; Sun, J. L.; Lin, X. H.; Yuan, C.-H.; Chuah, G. K.; Jaenicke, S. Influence of Facets and Heterojunctions in Photoactive Bismuth Oxyiodide. RSC Adv. 2015, 5, 88298-88305.
  • Wang, J.; Do, D. M.; Chuah, G. K.; Jaenicke, S. Core-Shell Composite as the Racemization Catalyst in the Dynamic Kinetic Resolution of Secondary Alcohols. ChemCatChem 2013, 5, 247-254.
  • Liu, H. H.; Chuah, G. K.; Jaenicke, S. N-Alkylation of Amines with Alcohols over Alumina-Entrapped Ag Catalysts using the “Borrowing Hydrogen" Methodology. J. Catal. 2012, 292, 130-137.
  • Fan, A.; Jaenicke, S.; Chuah, G. K. A Heterogeneous Pd-Bi/C Catalyst in the Synthesis of L-Lyxose and L-Ribose from Naturally Occurring D-sugars. Org. Biomol. Chem. 2011, 9, 7720-7726.
  • Ng, J. F.; Weil, T.; Jaenicke, S. Cationized Bovine Serum Albumin with Pendant RGD Groups forms Efficient Biocoatings for Cell Adhesion. J. Biomed. Mater. Res. B. 2011, 99B, 282-290.
  • Ng, J. F.; Nie, Y. T.; Chuah, G. K.; Jaenicke, S. A Wall-Coated Catalytic Capillary Microreactor for the Direct Formation of Hydrogen Peroxide. J. Catal. 2010, 269, 302-308.