Carbon nanotube hydrogen highways for identification of active sites responsible for selective bond breaking


Monday, October 11, 2021 - 8:45am


ENGR II 1519


Steven Crossley - University of Oklahoma


The conversion of renewable biomass, waste plastics, and many other important emerging streams to high value fuels and chemicals relies on advanced catalysts operating in very complicated environments. To provide cost effective and environmentally friendly solutions, catalysts must be designed to target specific C-O bonds in a complex mixture, have high reaction rates, and exhibit high catalyst stability. This presents a formidable challenge. Among the most promising families of catalysts to carry out this task are metals supported on active reducible supports, TiO2 or MoO3. These catalysts are also incredibly complex themselves. Because so many different surface features can present themselves under reaction conditions, the underlying reason behind their promising behavior often remains elusive. In this talk we introduce a unique approach to differentiate active sites by spacially separating them on carbon nanotube hydrogen highways. This allows us to differentiate active sites that are created on reducible oxide supports promoted by the metal from unique active sites that are created around the perimeter of metal nanoparticles. We show several examples relevant to the production of high value products from biomass and waste plastics to illustrate how this decoupling of active sites can help us to better understand and design improved catalysts.


Steven Crossley received his Ph.D. in chemical engineering with Daniel Resasco from the University of Oklahoma in 2009. From 2009-2011, he conducted research at ConocoPhillips, now Phillips 66, in the areas of fluid catalytic cracking and hydrocracking. In August 2011, Dr. Crossley joined the University of Oklahoma. His research focuses on reaction kinetics synthesis of nanomaterials for catalytic applications. His research involves evaluation of reaction mechanisms over zeolites or metals supported on reducible oxides for renewable fuels and polymer upcycling. Dr. Crossley is the recipient the NSF CAREER award and holds the Teigen Presidential Professorship and Sam A. Wilson professorship. He served as the CATL division Programming Chair for the 2019 and 2020 ACS fall national meetings and currently serves as member-at-large of the division. He also serves as secretary and president-elect for the Great Plains Catalysis Society. Dr. Crossley works to facilitate the success of Native American students in STEM fields and serves as faculty advisor for the University of Oklahoma’s award-winning American Indian Science and Engineering (AISES) chapter. He has published over 50 peer reviewed journal articles, including high impact journals such as Science, Science Advances, JACS, Nature Communications, Nature Catalysis and Energy and Environmental Science, and given over 60 oral presentations at national meetings and departmental seminars.

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