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Title: Mechanism of selective benzene hydroxylation catalyzed by iron-containing zeolites

Journal Article · · Proceedings of the National Academy of Sciences of the United States of America

A direct, catalytic conversion of benzene to phenol would have wide-reaching economic impacts. Fe zeolites exhibit a remarkable combination of high activity and selectivity in this conversion, leading to their past implementation at the pilot plant level. There were, however, issues related to catalyst deactivation for this process. Mechanistic insight could resolve these issues, and also provide a blueprint for achieving high performance in selective oxidation catalysis. Recently, we demonstrated that the active site of selective hydrocarbon oxidation in Fe zeolites, named α-O, is an unusually reactive Fe(IV)=O species. Here in this paper, we apply advanced spectroscopic techniques to determine that the reaction of this Fe(IV)=O intermediate with benzene in fact regenerates the reduced Fe(II) active site, enabling catalytic turnover. At the same time, a small fraction of Fe(III)-phenolate poisoned active sites form, defining a mechanism for catalyst deactivation. Density-functional theory calculations provide further insight into the experimentally defined mechanism. The extreme reactivity of α-O significantly tunes down (eliminates) the rate-limiting barrier for aromatic hydroxylation, leading to a diffusion-limited reaction coordinate. This favors hydroxylation of the rapidly diffusing benzene substrate over the slowly diffusing (but more reactive) oxygenated product, thereby enhancing selectivity. This defines a mechanism to simultaneously attain high activity (conversion) and selectivity, enabling the efficient oxidative upgrading of inert hydrocarbon substrates.

Research Organization:
Argonne National Laboratory (ANL), Argonne, IL (United States); SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
AC02-06CH11357; AC02-76SF00515; DGE-11474; CHE-1660611; Munger; Pollock; Reynolds; Robinson; Smith & Yoedicke Stanford Graduate Fellowship; 12L0715N; V417018N; G0A2216N; Gerhard Casper Stanford Graduate Fellowship; P41GM103393
OSTI ID:
1482162
Alternate ID(s):
OSTI ID: 1490261; OSTI ID: 1490638
Journal Information:
Proceedings of the National Academy of Sciences of the United States of America, Journal Name: Proceedings of the National Academy of Sciences of the United States of America Vol. 115 Journal Issue: 48; ISSN 0027-8424
Publisher:
National Academy of Sciences, Washington, DC (United States)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 10 works
Citation information provided by
Web of Science

References (30)

Kinetic isotope effects and mechanism of biomimetic oxidation of methane and benzene on FeZSM-5 zeolite journal August 1997
The role of iron in N2O decomposition on ZSM-5 zeolite and reactivity of the surface oxygen formed journal July 1990
Combined Experimental and Theoretical Study on Aromatic Hydroxylation by Mononuclear Nonheme Iron(IV)−Oxo Complexes journal May 2007
Direct Methane−Methanol and Benzene−Phenol Conversions on Fe−ZSM-5 Zeolite:  Theoretical Predictions on the Reaction Pathways and Energetics journal February 2000
Effect of steaming on the catalytic performance of ZSM-5 zeolite in the selective oxidation of phenol by nitrous oxide journal March 2014
Stability and reactivity of active sites for direct benzene oxidation to phenol in Fe/ZSM-5: A comprehensive periodic DFT study journal December 2011
Metalloenzymes: the entatic nature of their active sites. journal February 1968
The active site of low-temperature methane hydroxylation in iron-containing zeolites journal August 2016
Iron and Copper Active Sites in Zeolites and Their Correlation to Metalloenzymes journal December 2017
Nitrous oxide in oxidation chemistry and catalysis: application and production journal February 2005
Resonance Raman spectra of high- and low-spin ferric phenolates. Models for dioxygenases and nitrile hydratase journal May 1990
Geometric and Electronic Structure/Function Correlations in Non-Heme Iron Enzymes journal January 2000
Mechanism of Aromatic Hydroxylation by an Activated FeIVO Core in Tetrahydrobiopterin-Dependent Hydroxylases journal September 2003
Direct Spectroscopic Observation of Fe(III)−Phenolate Complex Formed From the Reaction of Benzene With Peroxide Species on Fe/ZSM-5 At Room Temperature journal May 2008
Kinetics of benzene to phenol oxidation over Fe-ZSM-5 catalyst journal August 2003
Mechanism of Aromatic Amino Acid Hydroxylation journal December 2003
Counterdiffusion of liquid hydrocarbons in type Y zeolite: Effect of molecular size, molecular type, and direction of diffusion journal July 1972
High-Valent Iron(IV)–Oxo Complexes of Heme and Non-Heme Ligands in Oxygenation Reactions journal July 2007
Model studies of iron-tyrosinate proteins journal February 1985
Mechanistic Insight into the Aromatic Hydroxylation by High-Valent Iron(IV)-oxo Porphyrin π-Cation Radical Complexes journal August 2007
Spectroscopic and electronic structure studies of aromatic electrophilic attack and hydrogen-atom abstraction by non-heme iron enzymes journal August 2006
A Density Functional Theory Study of Direct Oxidation of Benzene to Phenol by N 2 O on a [FeO] 1+ -ZSM-5 Cluster journal June 2010
Catalytic performance of sheet-like Fe/ZSM-5 zeolites for the selective oxidation of benzene with nitrous oxide journal March 2013
A hierarchical Fe/ZSM-5 zeolite with superior catalytic performance for benzene hydroxylation to phenol journal January 2009
Structural characterization of a non-heme iron active site in zeolites that hydroxylates methane journal April 2018
Stable Fe/ZSM-5 Nanosheet Zeolite Catalysts for the Oxidation of Benzene to Phenol journal March 2017
Magnetic circular dichroism spectroscopy as a probe of the geometric and electronic structure of non-heme ferrous enzymes journal October 1995
Nuclear resonance vibrational spectroscopy ? NRVS journal January 2005
Hydroxylation-Induced Migration: The NIH Shift: Recent experiments reveal an unexpected and general result of enzymatic hydroxylation of aromatic compounds journal September 1967
Mechanistic insights into the biomimetic catalytic hydroxylation of arenes by a molecular Fe(NHC) complex journal August 2017

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