The deactivation of Cu-Co alloy nanoparticles supported on ZrO2 for higher alcohols synthesis from syngas

The deactivations of Cu-Co alloy nanoparticles supported on ZrO2 for higher alcohols synthesis from syngas were investigated. The catalysts after reaction for 200 and 1500 h were compared and characterized by using N-2 adsorption and desorption, X-ray diffraction, transmission electron microscopy, energy dispersive spectrometer, inductively coupled plasma mass spectrometry and thermo gravimetric analysis techniques. The characterization results showed that the deactivation of the Cu-Co/ZrO2 catalyst in the reaction period of 200-1500 h was mainly attributed to cobalt volatilization in the form of its carbonyl at the reaction temperature. Sintering of the Cu-Co alloy and coke deposited on the catalyst surface could hardly be observed, meaning that sintering and coke deposition are not responsible for the deactivation of the catalyst. At the same time, the formation of Co2C on the surface of Cu-Co alloy might play a protective role for the decomposition of Cu-Co alloy and the volatilization of carbonyl cobalt. According to the results, some possible recommendations were proposed for the design of Cu-Co-based catalysts. (C) 2016 Elsevier Ltd. All rights reserved.