Department: Chemical and Biomolecular Engineering
Position: G. Whitney Snyder Professor, Chemical and Biomolecular Engineering
Director, Operando Molecular Spectroscopy and Catalysis Research Lab
Address: Mountaintop Campus
111 Research Drive
Bethlehem, PA 18015
Areas of Research
- Catalysis, Surface Science, and Interfacial Engine
- Materials Characterization
- Structure Property Correlations
- Environmental Catalysis
- Energy Science
- Engineering Processes for Enhanced Sustainability
In a career spanning three decades, Wachs has earned international renown for research into heterogeneous catalysis.
His research focuses on the catalysis science of mixed metal oxides (supported metal oxides , bulk metal oxides, polyoxometalates, zeolites and molecular sieves) for numerous catalytic applications (selective oxidation for manufacture of value-added chemicals, environmental catalysis (selective catalytic reduction of NOx and SOx), hydrocarbon conversion by solid acid catalysts for increased fuel energy content, olefin metathesis for on demand production of scarce propylene, olefin polymerization, conversion of methane to liquid aromatic fuels, biomass pyrolysis, water-gas shift for production of clean hydrogen and photocatalytic splitting of water to clean hydrogen.
The research aims to identify the catalytic active sites present on the heterogeneous catalyst surface to allow establishment of fundamental structure-activity/selectivity relationships that will guide the rational design of advanced catalysts. The research approach taken by the Wachs group is to simultaneously monitor the surface of the catalyst with spectroscopy under reaction conditions and online analysis of reactant conversion and product selectivity with online GC/mass spectrometer analysis. This new methodology has been termed operando spectroscopy and is allowing for the unprecedented development of molecular level structure-activity/selectivity relationships for catalysts. The spectroscopic techniques employed by the Wachs group for determination of the catalytic active sites and surface reaction intermediates are Raman, infrared (IR), ultra violet- visible (UV-vis), X-ray Absorption Spectroscopy (XANES/EXAFS), Nuclear Magnetic Resonance (NMR), Electron Paramagnetic Resonance (EPR) and Temperature Programmed Surface Reaction (TPSR). Isotopic labeling of Deuterium, Oxygen-18 and Carbon-13 is also used to track reaction pathways, determine rate-determining-steps and distinguish between spectator species and actual surface reaction intermediates.
The U.S. Environmental Protection Agency has honored Wachs with a Clean Air Excellence award for a catalytic process he invented that converts paper-mill pollutants into formaldehyde. The American Chemical Society (ACS) has given Wachs the George A. Olah Award for achievements in hydrocarbon and petroleum chemistry and the American Institute of Chemical Engineering (AIChE) has honored Wachs with the Catalysis and Reaction Engineering Division Practice Award . He is the recipient of multiple awards from local catalysis societies (Michigan, New York, Chicago and Philadelphia). In 2011, he was named a Fellow of the American Chemical Society (ACS), the highest honor bestowed by the society. In 2012, he was recognized by the German Alexander von Humbolt Foundation with a Humboldt Research Award and the International Vanadium Chemistry Organization with its Vanadis award.
Wachs has published more than 300 highly cited technical articles (H index of 80) and holds more than three dozen patents. Additional details about the Wachs group activities (publications, presentations, awards, etc.) can be found on the group site (lehigh.edu/operando).