کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
55678 | 47062 | 2011 | 8 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Pt and Pd nanoparticles supported on structured materials as catalysts for the selective reductive amination of carbonyl compounds Pt and Pd nanoparticles supported on structured materials as catalysts for the selective reductive amination of carbonyl compounds](/preview/png/55678.png)
Metal catalysts based on Pt and Pd nano-particles supported on structured microporous Beta zeolites and mesoporous MCM-41 materials, as well as specially designed γ-Al2O3 samples, were synthesized following a simple and economic procedure. Physico-chemical characterization of metal-composites (by XRD, IR spectroscopy, TEM, N2 adsorption, ICP, among others) indicated that both Pt and Pd nano-particles were adequately supported and homogeneously dispersed on supports. These metal/solid acid composites were applied as efficient catalysts under mild reaction conditions in the selective reductive amination of ketones, a useful industrial reaction for the synthesis of substituted amines and N-heterocycles. Results obtained showed that Pt/Al-Beta catalyst possesses the best catalytic activity (TON = 1610, with amine selectivities >95%) superior to that observed with commercial Pt/C and Pt/Al2O3 (TON ≈ 1000). Enhancements in Pt/Al-Beta samples were achieved by optimizing the Pt loading, and mainly the Si/Al molar ratio in solids. On the contrary, inferior catalytic activities were encountered with the Pt/Si-MCM-41 and Pt/Al-MCM-41 materials. The Pd incorporation on MCM-41 materials produced more active catalysts than the commercial Pd/C and Pd/Al2O3 samples. Finally, the study of Pt/ and Pd/γ-Al2O3 materials demonstrated that the treatments of support prior to the metal impregnation and the posterior calcinations processes were essentials to obtain efficient catalysts.
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► Pt and Pd-nanoparticles supported on well structured solid acids were applied in catalytic reductive aminations.
► Highly efficient Pt/Al-Beta catalysts could be prepared by optimizing Pt and Al contents in solids.
► Pd/MCM-41 catalysts also showed good activities in selective reductive aminations.
► The behaviour of Pt/ and Pd/Al2O3 samples strongly depends on the type of alumina pre-treatment used.
Journal: Catalysis Today - Volume 172, Issue 1, 25 August 2011, Pages 13–20