| The demand and consumption of energy are deeply increasing with the development of human society.Due to the limited storage of traditional fossil fuels,people are looking forward to fInd a renewable and economical new energy resource.Bio-ethanol is a good solution to this problem.However,more than 80%water in the bio-ethanol need to be removed before the use of it.Therefore,it is promising to develop a way to utilize bio-ethanol that is insensitive to the water content.In this article,we develop a convenience way to obtain CuCr catalysts for catalyzing bio-ethanol to form acetic acid.The reaction is also called the dehydrogenation-aldehyde-water shift(AWS)reaction of bio-ethanol.The main results are as follows:(1)Cu-based catalysts with different supportors and preparing methods were prepared and tested in the dehydrogenation-AWS reaction of ethanol.We obtained the highest catalytic activity by using the Cu70 catalyst that prepared by co-precipitating Cu and Cr nitrates.(2)The experimental and characteristic results showed that the dehydrogenation-AWS reaction of ethanol underwent two steps.First,the ethanol was dehydrogenated on the surface Cu to produce adsorbed aldehyde species.And then,the adsorbed aldehyde species was combined with hydroxyl groups from water to produce acetic acid.The rate determining step of the total reaction was the AWS process.(3)The best catalytic activity was obtained on follow conditions:70 wt%CuO content in the catalyst,623K,Ar atmosphere and 25 wt%ethanol content with 2mL·h-1 feed rates.The conversion of ethanol was high to 97%with the 48.6%selectivity of acetic acid.The aggregation of Cu particles resulted in the deactivation of the catalyst.(4)The mixed oxide catalyst of CuCr was obtained by calcinating Cu0.1/MIL-101 which derived from MIL-101 precursor.It demonstrated a better catalytic activity than CuCr catalysts in the dehydrogenation-AWS reaction of ethanol.It turned out that smaller particle size resulted in a better catalytic activity. |
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