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Cost-effective catalysis: towards avoiding spectator catalysts

Fri., Oct. 4, 2019 9:00 a.m.

Location: Education Building 193

Speaker: Dr. Olumide Ayodele

Topic: Cost-effective catalysis: towards avoiding spectator catalysts

Case study: Synergistic Computational-experimental Discovery of Highly Selective alloyed Pt Nanocluster and Single-Atom Catalysts for Acetylene Semihydrogenation

Date: Friday October 4th, 2019

Time: 9:00 a.m.

Room: ED 193

 

 

Abstract: Ethylene (C2H4) is an important feedstock in polymer industries and it also serves as an important intermediate in many industrial reactions. It is basically produced in large quantities via cracking of higher hydrocarbons. However, in the course of its production, there is inadvertent production of a little quantity of acetylene (approximately 1%). Even though this amount seems insignificant, it poses poison threats to the Ziegler–Natta catalysts. Thus, it is must be reduced to an acceptable minuscule level via semi-hydrogenation of acetylene (SHA) in an ethylene rich stream. Unfortunately, during SHA significant amounts of C2H4 were hydrogenated to undesirable by-product, ethane (C2H6). Presently, Pd-based catalysts have demonstrated excellent acetylene conversion (XC2H2) but at the expense of ethylene selectivity (SC2H4). In this presentation, a novel systematic and rational design of SHA catalysts that achieved very high XC2H2 without ethylene trade-off at industrially relevant process conditions will be discussed. Prior to the synthesis of the catalyst, density functional theory (DFT) was employed to predict the best catalyst system at the atomic level using Cu nanoparticles (NPs) to alloy Pt NPs supported on Al2O3. The DFT result predicted that with a Pt: Cu atomic ratio  1.1 (of 55 atoms, i.e., Pt28Cu27/Al2O3), the Pt d-band center shifted -2.2 eV relative to Fermi level leading to electron saturated Pt which allows only adsorption of ethylene via π bond thus resulting in 99.7% SC2H4 at nearly complete XC2H2. Based on the DFT predictions, a series of Pt-Cu/Al2O3 catalysts with different Pt/Cu atomic ratios were synthesized via cluster beam deposition, and their properties and activities were correlated. In order to further advance understanding of the Pt specific activity, a series of Pt supported on CeO2 catalysts were synthesized via another advanced technique – flame spray pyrolysis. The catalysts structure-activity-relationship correlation showed that besides the structural properties effects, the electronic effect also played a significant role on the SHA with Ce4+ => Ce3+ as the Pt loading reduced from 5.0 wt% to 0.25 wt%. This talk will also elaborate on the effect of Pt particle sizes determined by DRIFTS, HRTEM–HAADF–STEM–EELS on the desired C2H4 yield.

 

Biography: Olumide is presently a Visiting Scholar at the Faculty of Engineering and Applied Science, in the Advance Energy Research Laboratory (AERL), University of Regina. He is a Fellow and Diplomat at the Nanochemistry Research Group, Department of Micro and Nanofabrication, International Iberian Nanotechnology Laboratory (INL) Portugal. His research focus is synthesis, functionalization, and characterization of inorganic and hybrid nanocatalysts for clean energy technology applications such as semihydrogenation of acetylene, biofuel, carbon dioxide reduction to fuels & chemicals (F&C), low-temperature direct methane conversion to liquid F&C. He is also presently a Principal Investigator for an advanced catalysis for energy and environment project at the Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing, China funded by the National Natural Science Foundation of China. Prior to joining INL, he was a Senior Lecturer at the Chemical Engineering Department, University of Technology PETRONAS (UTP), Malaysia. His Postdoctoral study was funded by the Mitsubishi Corporation Education Trust Fund at the Center for Biofuel & Biochemical Research, UTP. During the period he was a visiting Research Scientist to the Clean Energy Research Center, University of Yamanashi, Kofu, Japan. He is founding Associate Editor of Malaysian Journal of Catalysis and presently Editorial Member of The Open Materials Science Journal. He received his Ph.D., MSc, BEng in Chemical Engineering from the University of Malaya, Malaysia, the University of Science Malaysia and the Federal University of Technology Minna, Nigeria, respectively.

 

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