Modifying the Surface of γ-Al2O3with Y2Sn2O7Pyrochlore: Monolayer Dispersion Behaviour of Composite Oxides.
To investigate the dispersion behaviour of composite oxides on supports, and to obtain better supports for Pd for CO oxidation, a series of Y2Sn2O7/Al2O3composite oxides with different Y2Sn2O7loadings were prepared by a deposition-precipitation method. XRD and X-ray photoelectron spectroscopic extrapolation methods revealed that, similar to single-component metal oxides, composite oxides can also disperse spontaneously on support surfaces to form a monolayer with a certain capacity. The monolayer dispersion capacity/threshold for Y2Sn2O7on the surface of γ-Al2O3is 0.109 mmol per 100 m2γ-Al2O3, corresponding to 7.2 wt % Y2Sn2O7loading. This is the first work to demonstrate monolayer dispersion of a composite oxide on a support. After combining Y2Sn2O7with γ-Al2O3, active oxygen species can be introduced onto the catalyst surfaces. Thus, the interaction between Pd and the support is strengthened, the dispersion of Pd is improved in comparison with the single-component Y2Sn2O7support, and a synergistic effect is induced between Pd and the composite support, which is beneficial to catalyst activity. By tuning the γ-Al2O3surface with different amounts of pyrochlore Y2Sn2O7, CO oxidation activity on 1 % Pd/Y2Sn2O7/Al2O3was improved. These findings may provide new insights into the design and preparation of effective supported noble metal catalysts with lower contents of noble metals.
College of Chemistry, Nanchang University, Nanchang, Jiangxi, 330031, P. R. China.
Xianglan
X
Xu
College of Chemistry, Nanchang University, Nanchang, Jiangxi, 330031, P. R. China.
Fang
F
Liu
College of Chemistry, Nanchang University, Nanchang, Jiangxi, 330031, P. R. China.
Jinshu
J
Tian
College of Chemistry, Nanchang University, Nanchang, Jiangxi, 330031, P. R. China.
Honggen
H
Peng
College of Chemistry, Nanchang University, Nanchang, Jiangxi, 330031, P. R. China.
Wenming
W
Liu
College of Chemistry, Nanchang University, Nanchang, Jiangxi, 330031, P. R. China.
Xiuzhong
X
Fang
College of Chemistry, Nanchang University, Nanchang, Jiangxi, 330031, P. R. China.
Ning
N
Zhang
College of Chemistry, Nanchang University, Nanchang, Jiangxi, 330031, P. R. China.
Xiang
http://orcid.org/0000-0002-4096-6147
X
Wang
composite oxides; monolayers; oxidation; palladium; supported catalysts