Catalyst design and development aims at more efficient and sustainable chemical processes. To this end, identification of the active catalytic site and design of catalysts with 100% atom efficiency has been a long-standing goal in heterogeneous catalysis. A novel approach to reaching this goal through single-atom heterogeneous catalysts has emerged in the recent literature. Atomically dispersed supported metal catalysts offer better resource utilization and new prospects for low-cost fuel processing and green chemicals production.1,2 In this presentation, metal catalysts stabilized as single atoms/cations on various supports will be reviewed drawing examples from a variety of reactions, including the low-temperature water-gas shift reactions,3-5 methanol steam reforming, and methanol and ethanol dehydrogenation reactions; direct methane conversion to oxygenates, and several selective hydrogenation reactions on single-atom alloys.6-8 We will demonstrate how reaction mechanisms involving single metal atoms/cations, transcend support structure and composition as long as the metal atom site, is allowed to form stably. A unique “signature” of the metal (Au, Pt, Pd, etc.) at the atomic state is preserved, distinct however from the corresponding extended metal catalyst.1,4,6-8 Novel synthesis methods will be discussed as will be the stability of atomically dispersed catalysts in various supports and reaction environments.
1. M. Flytzani-Stephanopoulos and Bruce Gates, Annu. Rev. Chem. Biomol. Eng. 2012, 3
2. J. Liu, ACS Catal., 2017, 7, 34–59
3. Q. Fu et al., Science 2003, 301, 935
4. M.Yang et al., Science 2014, 346, 1498
5. M.Yang et al., J. Am. Chem. Soc. 2015, 137, 3470
6. G. Kyriakou et al., Science 2012, 335, 1209
7. F. Lucci, J. Liu et al., Nat. Commun. 2015, 6, 8550
8. J. Liu et al., J. Am. Chem. Soc. 2016, 138 (20), pp 6396
Dr. Flytzani-Stephanopoulos is a Distinguished Professor and the Robert and Marcy Haber Endowed Professor in Energy Sustainability in the School of Engineering at Tufts University. She directs the Tufts Nano Catalysis and Energy Laboratory, which investigates new catalyst materials for the production of hydrogen and green chemicals. Pioneering work from her lab has demonstrated the use of single atom heterogeneous catalysts for several reactions of interest to fuels and chemicals processing. These catalysts with 100% atomic efficiency of precious metals and high selectivity to the desired product will enable more efficient and sustainable chemical process development. Dr. Flytzani-Stephanopoulos joined the Chemical Engineering faculty at Tufts in 1994. She holds ten patents and has written more than 170 technical papers. She has been an editor of the journal Applied Catalysis B: Environmental since 2002, and is an associate editor of Science Advances. She is the recipient of many awards and distinctions, including the Tufts Distinguished Scholar award, the Henry J. Albert award of the International Precious Metals Institute, the Giuseppe Parravano Memorial award of the Michigan Catalysis Society, the Graduate Teaching and Mentoring Award of the Tufts School of Engineering, and the Carol Tyler award of the IPMI. She is a Fellow of the AAAS and the AIChE, and a member of the US National Academy of Engineering.