Abstract
Ethanol carbonylation is a potential route to valuable C3 products. Here, Rh supported on porous, Cs-exchanged heteropolyacid Cs3PW12O40, is demonstrated as an effective catalyst for vapor-phase ethanol carbonylation, with higher selectivity and conversion to propionates than existing catalysts. Residual acidity or a Mo polyatom was strongly detrimental to yields. Propionate selectivity was maximized at 96% at 170 °C and with added H2O. The catalyst displayed stable selectivity over 30 h on stream and up to 77% conversion. Ethyl iodide is a required co-catalyst but at levels as low as 2% relative to ethanol. XPS and in situ XANES indicate partial Rh reduction, consistent with the formation of low-valent reactive intermediates and slow deactivation through formation of Rh nanoparticles. With further optimization and understanding, these Rh/heteropolyacid catalysts may lead to stable and selective catalysts for the production of propionates through ethanol carbonylation.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1-8 |
| Number of pages | 8 |
| Journal | Journal of Catalysis |
| Volume | 325 |
| DOIs | |
| State | Published - May 1 2015 |
Funding
This work was supported by The Dow Chemical Company . Portions of this work were performed at the DuPont–Northwestern–Dow Collaborative Access Team (DND-CAT) located at Sector 5 of the Advanced Photon Source (APS). DND-CAT is supported by E.I. DuPont de Nemours & Co. , The Dow Chemical Company and Northwestern University . Use of the APS, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by Argonne National Laboratory, was supported by the U.S. DOE under Contract No. DE-AC02-06CH11357 . The authors highly appreciate Dr. Qing Ma at DND-CAT of APS for his X-ray absorption spectroscopy expertise. Metal analysis (ICP-MS) was performed at the Northwestern University Quantitative Bioelemental Imaging Center generously supported by NASA Ames Research Center NNA06CB93G . Metal analysis (ICP-AES) and Solid State NMR were performed at the Northwestern University Integrated Molecular Structure Education and Research Center with funding provided by NSF DMR-0521267 . The CleanCat Core facility acknowledges funding from the Department of Energy ( DE-FG02-03ER15457 ) used for the purchase of the Altamira AMI-200. This work made use of the J.B. Cohen X-Ray Diffraction Facility supported by the MRSEC program of the National Science Foundation ( DMR-1121262 ) at the Materials Research Center of Northwestern University. This XPS work was performed in the Keck-II facility of NU ANCE Center at Northwestern University. The NU ANCE Center is supported by NSEC ( NSF EEC-0647560 ), MRSEC ( NSF DMR-1121262 ), the Keck Foundation , the State of Illinois , and Northwestern University .
Keywords
- Carbonylation
- Ethanol
- Heteropolyacid
- Iodide
- Rhodium
ASJC Scopus subject areas
- Catalysis
- Physical and Theoretical Chemistry