Selective catalytic hydroalkylation and deoxygenation of substituted phenols to bicycloalkanes

Journal Article · Sun Apr 01 04:00:00 EDT 2012 · Journal of Catalysis

DOI:https://doi.org/10.1016/j.jcat.2012.01.005· OSTI ID:1039847

Zhao, Chen; Camaioni, Donald M; Lercher, Johannes A

Phenol and substituted phenols are hydroalkylated and hydrodeoxygenated to bi-cycloalkanes in a tandem reaction over Pd nanoclusters supported on a large-pore molecular sieve HBEA at 473-523 K using water as solvent. The HBEA-supported Pd catalyst (metal-acid ratio: 1:22 mol/mol) optimally balances the competing rates of metal catalyzed hydrogenation as well as of solid acid-catalyzed dehydration and carbon-carbon coupling to combine hydrodeoxygenation and dimerization of phenol derivatives to C{sub 12}-C{sub 18} bicycloalkanes in a single reaction sequence. A detailed kinetic study of the elementary reactions of (substituted) phenol and their potential products (cyclohexanol, cyclohexanone, and cyclohexene) demonstrates that phenol selectively reacts with the in situ generated cyclohexanol or cyclohexene on Broensted acid sites. The acid-catalyzed alkylation of phenol with alcohol intermediates and alcohol dehydration are parallel reactions, which are subtly influenced by the competing hydrogenation reactions as well as by the presence of water as solvent. IR spectroscopy of adsorbed species and preliminary molecular modeling indicate that phenol and cyclohexanol enrichment in the large pores of zeolite HBEA is critical for the high activity and hydroalkylation selectivity.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1039847
• Report Number(s): PNNL-SA-86860; KC0302010
• Journal Information: Journal of Catalysis, Journal Name: Journal of Catalysis Vol. 288; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ALCOHOLS
ALKYLATION
Alkylation
BROENSTED ACIDS
C-C bond coupling
CATALYSTS
CYCLOHEXANOL
CYCLOHEXANONE
DEHYDRATION
DIMERIZATION
HYDROGENATION
Hydroalkylation
Hydrogenation
KINETICS
MOLECULAR SIEVES
PHENOL
PHENOLS
Phenol
SPECTROSCOPY
WATER
ZEOLITES
Zeolite