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-12-C-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 Bronsted 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. (C) 2012 Elsevier Inc. All rights reserved.     «

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...     »

ISI Document Delivery No.: 920VE Times Cited: 6 Cited Reference Count: 34 Zhao, Chen Camaioni, Donald M. Lercher, Johannes A. Kang, Zhai/G-8010-2012 Technische Universitat Munchen; US Department of Energy's (DOE) Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences This work was supported by Technische Universitat Munchen in the framework of the European Graduate School for Sustainable Energy. The authors thank Prof. Andreas Jentys (TU Munchen, Germany) providing helpful advice in the molecular modeling section. In addition, we thank the US Department of Energy's (DOE) Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences for supporting DMC to collaborate on this work and contribute to the modeling study. The Pacific Northwest National Laboratory is operated by Battelle for DOE. 6 Academic press inc elsevier science San diego     «

ISI Document Delivery No.: 920VE Times Cited: 6 Cited Reference Count: 34 Zhao, Chen Camaioni, Donald M. Lercher, Johannes A. Kang, Zhai/G-8010-2012 Technische Universitat Munchen; US Department of Energy's (DOE) Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences This work was supported by Technische Universitat Munchen in the framework of the European Graduate School for Sustainable Energy. The authors thank Prof. Andreas Jentys (TU Munchen, Germany) pr...     »