Hits:

Indexed by:期刊论文

Date of Publication:2018-01-01

Journal:RSC ADVANCES

Included Journals:SCIE、EI

Volume:8

Issue:15

Page Number:8152-8163

ISSN No.:2046-2069

Abstract:In this paper, Ni/Al2O3 catalysts (15 wt% Ni) with different Re loadings were prepared to investigate the effect of Re on the structure and catalytic performance of Ni-Re/Al2O3 catalysts for the reductive amination of monoethanolamine. Reaction results reveal that the conversion and ethylenediamine selectivity increase significantly with increasing Re loading up to 2 wt%. Ni-Re/Al2O3 catalysts show excellent stability during the reductive amination reaction. The characterization of XRD, DR UV-Vis spectroscopy, H2-TPR, and acidity-basicity measurements indicates that addition of Re improves the Ni dispersion, proportion of octahedral Ni2+ species, reducibility, and acid strength for Ni-Re/Al2O3 catalysts. The Ni15 and Ni15-Re2 catalysts were chosen for in-depth study. The results from SEM-BSE, TEM, and CO-TPD indicate that smaller Ni-0 particle size and higher Ni-0 surface area are obtained in the reduced Ni-Re/Al2O3 catalysts. Results from in situ XPS and STEM-EDX line scan suggest that Re species show a mixture of various valances and have a tendency to aggregate on the surface of Ni-0 particles. During reaction, the Ni-0 particles on the Al2O3 support are stabilized and the sintering process is effectively suppressed by the incorporation of Re. It could be concluded that sufficient Ni-0 sites, the collaborative effect of Ni-Re, and brilliant stability contribute to the excellent catalytic performance of Ni-Re/Al2O3 catalysts for the reductive amination of monoethanolamine.