(513cj) Atomically Precise Design of Heterogeneous Catalysts for Enhanced Pairwise Selective Addition of Parahydrogen to Unsaturated Hydrocarbons
AIChE Annual Meeting
2020 Virtual AIChE Annual Meeting
Catalysis and Reaction Engineering Division
Catalyst Synthesis and Design II: Zeolites and Other Oxides
Wednesday, November 18, 2020 - 9:30am to 9:45am
Well-defined shapes are superior in catalysis studies as they enable investigations on catalytic activities down to surface facet level. Here, a modified atomic layer deposition technique was developed to achieve ultra-low loadings (8-16 ppm) of platinum on shaped ceria nanocrystals. By using octahedra and cubes, which expose exclusively (111) and (100) surface facets respectively, the effect of CeO2 surface on the stability of isolated Pt atoms was investigated. A Pt/CeO2(111) catalyst with only 8 ppm of Pt exhibited an unprecedented high pairwise selectivity for continuous-flow hydrogenation (6.1 %), which is a factor of two higher than the best previously reported value for a monometallic heterogeneous Pt catalyst. Strong interaction between Pt and the CeO2 (111) is found to increase the stability of atomically dispersed Pt under reducing conditions and affords significantly higher NMR signal enhancement than CeO2 (100).