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solution was heated in a water bath at 80 ꢀC for 4 h. The
resulting product, denoted as ZG-3, was dried in air and
calcined under nitrogen at 400 C for 3 h.
Conflicts of interest
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There are no conicts of interest to declare.
Preparation of Cu/ZrO2-RGO
Acknowledgements
The three ZrO2-RGO products, ZG-1, ZG-2, and ZG-3, (6.44 g)
were each mixed separately with Cu(NO3)2$3H2O (4.84 g) and
ground together using a ball mill. Cu/ZrO2-RGO composites,
independently named as CZG-1, CZG-2, CZG-3, were prepared
This work was supported by the National Natural Science
Foundation of China (21576229).
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by calcination under nitrogen at 450 C for 3 h and hydrogen
Notes and references
reduction at 250 ꢀC for 4 h. To highlight the importance of the
structure and composition of CZG, the corresponding ZrO2, Cu/
ZrO2, and Cu/RGO materials were made and compared to the
composite materials. The preparation procedure for the ZrO2,
Cu/ZrO2, and Cu/RGO materials can be found in the ESI.† The
schematic diagram of Cu/ZrO2-RGO catalyst is shown in Fig. 10.
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Catalytic evaluation
Cu/ZrO2-RGO was used as a catalyst for the dehydrogenation of
diethanolamine. Diethanolamine and sodium hydroxide (1 : 2.5
mol : mol) were reacted with 4.5 g catalyst at 160 ꢀC for 4 h. The
content of sodium iminodiacetic acid (DSIDA) in the reaction
solution was analyzed by high-performance liquid chromatog-
raphy (HPLC).
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30446 | RSC Adv., 2019, 9, 30439–30447
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