Metal-Organic Framework Supported Cobalt Catalysts for the Oxidative Dehydrogenation of Propane at Low Temperature.
Zr-based metal-organic frameworks (MOFs) have been shown to be excellent catalyst supports in heterogeneous catalysis due to their exceptional stability. Additionally, their crystalline nature affords the opportunity for molecular level characterization of both the support and the catalytically active site, facilitating mechanistic investigations of the catalytic process. We describe herein the installation of Co(II) ions to the Zr6nodes of the mesoporous MOF, NU-1000, via two distinct routes, namely, solvothermal deposition in a MOF (SIM) and atomic layer deposition in a MOF (AIM), denoted as Co-SIM+NU-1000 and Co-AIM+NU-1000, respectively. The location of the deposited Co species in the two materials is determined via difference envelope density (DED) analysis. Upon activation in a flow of O2at 230 °C, both materials catalyze the oxidative dehydrogenation (ODH) of propane to propene under mild conditions. Catalytic activity as well as propene selectivity of these two catalysts, however, is different under the same experimental conditions due to differences in the Co species generated in these two materials upon activation as observed byin situX-ray absorption spectroscopy. A potential reaction mechanism for the propane ODH process catalyzed by Co-SIM+NU-1000 is proposed, yielding a low activation energy barrier which is in accord with the observed catalytic activity at low temperature.
Department of Chemistry, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States.
Zhanyong
Z
Li
Department of Chemistry, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States.
Aaron W
AW
Peters
Department of Chemistry, Supercomputing Institute, and Chemical Theory Center, University of Minnesota , Minneapolis, Minnesota 55455, United States.
Varinia
V
Bernales
Department of Chemistry, Supercomputing Institute, and Chemical Theory Center, University of Minnesota , Minneapolis, Minnesota 55455, United States.
Manuel A
MA
Ortuño
Department of Chemical and Biological Engineering, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States.
Neil M
NM
Schweitzer
Department of Chemistry, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States.
Matthew R
MR
DeStefano
X-ray Science Division, Advanced Photon Source, Argonne National Laboratory , Argonne, Illinois 60439-4858, United States.
Leighanne C
LC
Gallington
X-ray Science Division, Advanced Photon Source, Argonne National Laboratory , Argonne, Illinois 60439-4858, United States.
Ana E
AE
Platero-Prats
X-ray Science Division, Advanced Photon Source, Argonne National Laboratory , Argonne, Illinois 60439-4858, United States.
Karena W
KW
Chapman
Department of Chemistry, Supercomputing Institute, and Chemical Theory Center, University of Minnesota , Minneapolis, Minnesota 55455, United States.
Christopher J
CJ
Cramer
Department of Chemistry, Supercomputing Institute, and Chemical Theory Center, University of Minnesota , Minneapolis, Minnesota 55455, United States.
Laura
L
Gagliardi
Department of Chemistry, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States.
Joseph T
JT
Hupp
Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States; Department of Chemistry, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
Omar K
OK
Farha