The influences of adding sodium to zirconia on the acid-base properties of the surface and on the catalytic conversion of ethanol and acetone were investigated. The rates of ethanol dehydration, dehydrogenation and co...The influences of adding sodium to zirconia on the acid-base properties of the surface and on the catalytic conversion of ethanol and acetone were investigated. The rates of ethanol dehydration, dehydrogenation and coupling were evaluated in a fixed-bed flow reactor operating at temperatures from 613 to 673 K. The rate of acetone condensation was evaluated in the same reactor operating at 473-573 K. Addition of 1.0 wt% Na to ZrO2 decreased the rate of ethanol dehydration by more than an order of magnitude, which was consistent with a neutralization of acid sites evaluated by ammonia adsorption microcalorimetry. Addition of 1.0 wt% Na to ZrO2 also increased the base site density quantified by carbon dioxide adsorption microcalorimetry and the rate of acetone condensation. Although the rate of ethanol coupling was not increased by the addition of Na, the overall selectivity of ethanol to butanol was improved over the 1.0 wt% Na/ZrO2 sample because of the significant inhibition of ethanol dehydration.展开更多
Biobutanol is attracting increasingly interest as a source of renewable energy and biofuels because of its many advantages over bioethanol that include higher energy density, fuel efficiency, and reduced engine damage...Biobutanol is attracting increasingly interest as a source of renewable energy and biofuels because of its many advantages over bioethanol that include higher energy density, fuel efficiency, and reduced engine damages. Currently, there is a growing interest in producing biobutanol from bioethanol, in view of the tremendous potential benefits of this transformation for the bulk production of biobutanol in a target specific manner. This perspective paper describes recent progress for the ethanol to butanol process. The different catalysts, including homogeneous and heterogeneous catalytic systems, for ethanol to butanol are outlined and compared, and the key issues and requirements for future developments are highlighted. A major challenge for further development and application of ethanol to butanol process is to find an optimal balance between different catalytic functions and to suppress the formation of side products that has plagued most catalytic bioethanol upgrading systems. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B. V. and Science Press. All rights reserved.展开更多
1‐Butanol is a potential bio‐based fermentation product obtained from cellulosic biomass.As a value‐added chemical,2‐ethyl‐1‐hexanol(2‐EH)can be produced by Guerbet conversion from 1‐butanol.This work reports ...1‐Butanol is a potential bio‐based fermentation product obtained from cellulosic biomass.As a value‐added chemical,2‐ethyl‐1‐hexanol(2‐EH)can be produced by Guerbet conversion from 1‐butanol.This work reports the enhanced catalytic Guerbet reaction of 1‐butanol to 2‐EH by a series of Cp^(*)Ir complexes(Cp^(*):1,2,3,4,5‐pentamethylcyclopenta‐1,3‐diene)coordinated to bipyridine‐type ligands bearing an ortho‐hydroxypyridine group with an electron‐donating group and a Cl−anion.The catalytic activity of the Cp^(*)Ir complex increased by increasing the electron density of the bipyridine ligand when functionalized with the para‐NMe2 and ortho‐hydroxypyridine groups.A record turnover number of 14047 was attained.A mechanistic study indicated that the steric effect of the ethyl group on theα‐C of 2‐ethylhexanal(2‐EHA)and the conjugation effect of C=C–C=O in 2‐ethylhex‐2‐enal(2‐EEA)benefits the high selectivity of 2‐EH from 1‐butanol by inhibiting the cross‐aldol reaction of 2‐EHA and 2‐EEA with butyraldehyde.Nuclear magnetic resonance study revealed the formation of a carbonyl group in the bipyridine‐type ligand via the reaction of the Cp^(*)Ir complex with KOH.展开更多
基金the Chemical Sciences,Geosciences and Biosciences Division,Office of Basic Energy Sciences,Office of Science,U.S.Department of Energy,grant no.DEFG0295ER14549
文摘The influences of adding sodium to zirconia on the acid-base properties of the surface and on the catalytic conversion of ethanol and acetone were investigated. The rates of ethanol dehydration, dehydrogenation and coupling were evaluated in a fixed-bed flow reactor operating at temperatures from 613 to 673 K. The rate of acetone condensation was evaluated in the same reactor operating at 473-573 K. Addition of 1.0 wt% Na to ZrO2 decreased the rate of ethanol dehydration by more than an order of magnitude, which was consistent with a neutralization of acid sites evaluated by ammonia adsorption microcalorimetry. Addition of 1.0 wt% Na to ZrO2 also increased the base site density quantified by carbon dioxide adsorption microcalorimetry and the rate of acetone condensation. Although the rate of ethanol coupling was not increased by the addition of Na, the overall selectivity of ethanol to butanol was improved over the 1.0 wt% Na/ZrO2 sample because of the significant inhibition of ethanol dehydration.
基金supported by the National Natural Science Foundation of China(21273044,21473035,and 91545108)SINOPEC(X514005)the Open project of State Key Laboratory of Chemical Engineering(SKL-Ch E-15C02)
文摘Biobutanol is attracting increasingly interest as a source of renewable energy and biofuels because of its many advantages over bioethanol that include higher energy density, fuel efficiency, and reduced engine damages. Currently, there is a growing interest in producing biobutanol from bioethanol, in view of the tremendous potential benefits of this transformation for the bulk production of biobutanol in a target specific manner. This perspective paper describes recent progress for the ethanol to butanol process. The different catalysts, including homogeneous and heterogeneous catalytic systems, for ethanol to butanol are outlined and compared, and the key issues and requirements for future developments are highlighted. A major challenge for further development and application of ethanol to butanol process is to find an optimal balance between different catalytic functions and to suppress the formation of side products that has plagued most catalytic bioethanol upgrading systems. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B. V. and Science Press. All rights reserved.
文摘1‐Butanol is a potential bio‐based fermentation product obtained from cellulosic biomass.As a value‐added chemical,2‐ethyl‐1‐hexanol(2‐EH)can be produced by Guerbet conversion from 1‐butanol.This work reports the enhanced catalytic Guerbet reaction of 1‐butanol to 2‐EH by a series of Cp^(*)Ir complexes(Cp^(*):1,2,3,4,5‐pentamethylcyclopenta‐1,3‐diene)coordinated to bipyridine‐type ligands bearing an ortho‐hydroxypyridine group with an electron‐donating group and a Cl−anion.The catalytic activity of the Cp^(*)Ir complex increased by increasing the electron density of the bipyridine ligand when functionalized with the para‐NMe2 and ortho‐hydroxypyridine groups.A record turnover number of 14047 was attained.A mechanistic study indicated that the steric effect of the ethyl group on theα‐C of 2‐ethylhexanal(2‐EHA)and the conjugation effect of C=C–C=O in 2‐ethylhex‐2‐enal(2‐EEA)benefits the high selectivity of 2‐EH from 1‐butanol by inhibiting the cross‐aldol reaction of 2‐EHA and 2‐EEA with butyraldehyde.Nuclear magnetic resonance study revealed the formation of a carbonyl group in the bipyridine‐type ligand via the reaction of the Cp^(*)Ir complex with KOH.
