Nano-particle Pd/?-Al2O3 monometallic and Pd-Cu/?-Al2O3 bimetall ic catalysts were prepared by solvated metal atom impregnation (SMAI) method. Th e results of XRD measurement indicated that Pd- Cu alloy was formed in ...Nano-particle Pd/?-Al2O3 monometallic and Pd-Cu/?-Al2O3 bimetall ic catalysts were prepared by solvated metal atom impregnation (SMAI) method. Th e results of XRD measurement indicated that Pd- Cu alloy was formed in the bim etallic catalysts and the crystalline particle size of the alloy increased as Cu contents increased with average diameters < 6.0nm for all the samples. XPS and Auger spectra showed that Pd was in zero- valent state, Cu existed mainly in z ero- valent state and partially in monovalent state Cu+. The Pd/?-Al2O3 and Pd-Cu/?-Al2O3 catalysts exhibited higher activity for CO oxidation at low temperature. The activity of Pd-Cu/?-Al2O3 bimetallic catalyst was hig her than that of Pd/?-Al2O3 monometallic catalyst. The Pd-Cu/?-Al2O3 c atalyst with Pd/Cu atomic ratio of 1∶1 showed the highest activity.展开更多
In this work, Pd–Cu/γ-Al2O3 is prepared by the impregnation method and investigated for selective oxygenization of cyclopentene to cyclopentanone. A series of bimetallic Pd–Cu/γ-Al2O3 nanocatalysts were prepared a...In this work, Pd–Cu/γ-Al2O3 is prepared by the impregnation method and investigated for selective oxygenization of cyclopentene to cyclopentanone. A series of bimetallic Pd–Cu/γ-Al2O3 nanocatalysts were prepared and the structures characterized by XRD, XPS and TEM. We determined that the obtained Pd–Cu/γ-Al2O3（molar ratio Pd：Cu = 5：1） was an efficient catalyst for the oxygenization of cyclopentene to cyclopentanone with 95% selectivity and 85% conversion（100 °C, 1 MPa initial O2 pressure, 7 h）.展开更多
Bimetallic Pd-Cu/Al_(2)O_(3) was prepared by wetness impregnation method and its catalytic activity on coupling reaction of pyridine to 2,2'-bipyridine was assessed in view of the effects of different molar ratios...Bimetallic Pd-Cu/Al_(2)O_(3) was prepared by wetness impregnation method and its catalytic activity on coupling reaction of pyridine to 2,2'-bipyridine was assessed in view of the effects of different molar ratios of Pd:Cu.It is found that Pd-Cu/Al_(2)O_(3) has the small particle size and good dispersion through the characterization.Compared with Pd/Al_(2)O_(3),Pd-Cu(1:2)/Al_(2)O_(3) is the preferable catalyst under the optimum conditions of 1 MPa N2 pressure,310℃and 16 h.The conversion of pyridine is 35.4%,and the selectivity for 2,2'-Bipyridine is up to 99%,which is much higher activity than Pd/Al_(2)O_(3).The directly coupled synthesis meets the requirements of the atomic economy better.The addition of Cu also reduces the dosage of Pd and lowers the cost.It is worth noting that the recycled Pd-Cu/Al_(2)O_(3) catalyst still shows high activity and stability after three times.展开更多
文摘Nano-particle Pd/?-Al2O3 monometallic and Pd-Cu/?-Al2O3 bimetall ic catalysts were prepared by solvated metal atom impregnation (SMAI) method. Th e results of XRD measurement indicated that Pd- Cu alloy was formed in the bim etallic catalysts and the crystalline particle size of the alloy increased as Cu contents increased with average diameters < 6.0nm for all the samples. XPS and Auger spectra showed that Pd was in zero- valent state, Cu existed mainly in z ero- valent state and partially in monovalent state Cu+. The Pd/?-Al2O3 and Pd-Cu/?-Al2O3 catalysts exhibited higher activity for CO oxidation at low temperature. The activity of Pd-Cu/?-Al2O3 bimetallic catalyst was hig her than that of Pd/?-Al2O3 monometallic catalyst. The Pd-Cu/?-Al2O3 c atalyst with Pd/Cu atomic ratio of 1∶1 showed the highest activity.
基金financial assistance from the National Natural Science Foundation of China (Nos. 21272050, 21371044, 21472033 and 21571047)
文摘In this work, Pd–Cu/γ-Al2O3 is prepared by the impregnation method and investigated for selective oxygenization of cyclopentene to cyclopentanone. A series of bimetallic Pd–Cu/γ-Al2O3 nanocatalysts were prepared and the structures characterized by XRD, XPS and TEM. We determined that the obtained Pd–Cu/γ-Al2O3（molar ratio Pd：Cu = 5：1） was an efficient catalyst for the oxygenization of cyclopentene to cyclopentanone with 95% selectivity and 85% conversion（100 °C, 1 MPa initial O2 pressure, 7 h）.
基金by the Natural Science Foundation of the Higher Education Institutions of Anhui Province(No.KJ2021A0132)the Key Research and Development Program of Anhui Province(No.202104a05020070)the National and Anhui Province College Student Innovation Training Program(Nos.202110364055 and S202010364145)。
文摘Bimetallic Pd-Cu/Al_(2)O_(3) was prepared by wetness impregnation method and its catalytic activity on coupling reaction of pyridine to 2,2'-bipyridine was assessed in view of the effects of different molar ratios of Pd:Cu.It is found that Pd-Cu/Al_(2)O_(3) has the small particle size and good dispersion through the characterization.Compared with Pd/Al_(2)O_(3),Pd-Cu(1:2)/Al_(2)O_(3) is the preferable catalyst under the optimum conditions of 1 MPa N2 pressure,310℃and 16 h.The conversion of pyridine is 35.4%,and the selectivity for 2,2'-Bipyridine is up to 99%,which is much higher activity than Pd/Al_(2)O_(3).The directly coupled synthesis meets the requirements of the atomic economy better.The addition of Cu also reduces the dosage of Pd and lowers the cost.It is worth noting that the recycled Pd-Cu/Al_(2)O_(3) catalyst still shows high activity and stability after three times.
