Monolayer dispersion thresholds and threshold effect displayed by supported catalysts

Abstract

The principle of spontaneous monolayer dispersion holds that active components of many supported catalysts will disperse spontaneously onto the surface of the carrier. The monolayer dispersion threshold of the active component on the surface of the carrier can be measured by X-ray diffraction phase-quantitative extrapolation method, etc. By measuring the monolayer dispersion threshold, beneficial information on the surface structure and dispersion of supported catalysts can be obtained, and the optimal preparative processing conditions of the catalysts can be chosen. The proportion of the active component of many supported catalysts can be optimized while its monolayer dispersion threshold is observed. Mutation values of many physicochemical properties of supported catalysts are related to monolayer dispersion thresholds; the threshold effect on catalysts is apparent, and the proposal regarding the threshold effect provides instruction for the research on catalysts.

References

1. Xie Youchang, Yang Naifang, Liu Yingjun, Tang Youqi . Spontaneousdispersion of some active components onto the surfaces of carriers. Scientia Sinica (Series B), 1983, 26(4): 337–350
2. Xie Youchang, Gui Linlin, Bo Naiyu, Liu Wanqi, Tang Youqi . Studies of the structure and the mechanismof highly effective catalyst of polyethylene. Scientia Sinica, 1979, (7): 665–673 (in Chinese)
3. Liu Yingjun, Xie Youchang, Ming Jing, Liu Jun, Tang Youqi . Determination of the maximum monolayerdispersion of MoO₃ on γ-Al₂O₃ by X-ray diffraction. J Catal, 1982, 3(4): 262–267 (in Chinese)
4. Liu Yingjun, Xie Youchang, Li Ce, Zou Zhiyang, Tang Youqi . Monolayer dispersion of MoO₃ on γ-Al₂O₃ from different sources. J Catal, 1984, 5(3): 234–239 (in Chinese)
5. Liu Yingjun, Zhao Ming, Guo Qinlin, Gui Linlin, Xie Youchang, Tang Youqi . Determination of the maximum monolayer dispersion and dispersed statefor WO₃ on γ-Al₂O₃. Acta Chim Sin, 1985, 43: 728–732 (in Chinese)
6. Liu Yingjun, Xie Youchang, Xie Gang, Tang Youqi . Studiesof the interaction between MoO₃ and variouscarriers and determination of the monolayer dispersion capacitiesof MoO₃. J Catal, 1985, 6(2): 101–107 (in Chinese)
7. Liu Yingjun, Fu Lijun, Tang Youqi . NiO dispersion on surface of titania. J Mol Catal, 1989, 3(3): 173–180 (in Chinese)
8. Wang Chunming, Zhao Biying, Xie Youchang . Advances in the studies of spontaneous monolayer dispersionof oxides and salts on supports. J Catal, 2003, 24(6): 475–482 (in Chinese)
9. Liu Yingjun, Wu Jiangping, Guo Qinlin, Gui Linlin, Tang Youqi . XRD and XPS studies of WO₃ on silica. J Catal, 1987, 8(1): 14–19 (in Chinese)
10. Deng Cun . Dispersion threshold–an important parameter in research ofcatalysts. Chemistry, 1991 (10): 26–31 (in Chinese)
11. Deng Cun, Chen Qiaoping, Liu Yingjun . Dispersion and thresholds for WO₃ on complex supports of TiO₂/γ-Al₂O₃ and TiO₂/SiO₂. J Mol Catal, 1994, 8(5): 387–392 (in Chinese)
12. Zhang Yufen, Xie Youchang, Zhang Yang, Zhang Delong, Tang Youqi . Studies of the reduction property andthe state of existence of oxides on carriers. Scientia Sinica (Series B), 1986, (8): 805–813 (in Chinese)
13. Deng Cun, Duan Lianyun, Xu Xianping, Xie Youchang . Dispersionstate and maximum dispersion capacity of MoO₃ on the surface of TiO₂/γ-Al₂O₃ complex support. Natur Gas Chem Ind, 1992, 17(6): 6–11 (in Chinese)
14. Deng Cun, Duan Lianyun, Wang Chuanbao, Xu Xianping, Xie Youchang . Preparation of complex supportTiO₂/γ-Al₂O₃ by gas phase adsorption and state of TiO₂ on γ-Al₂O₃ surface. J Mol Catal, 1992, 6(1): 15–22 (in Chinese)
15. Deng Cun, Duan Lianyun, Xu Xianping, Xie Youchang . Preparationof TiO₂/SiO₂ complexsupport by gas phase adsorption and dispersion state of MoO₃ on surface of complex support. J Catal, 1993, 14(4): 281–286 (in Chinese)
16. Zhou Zhenhua, Yan Weihong, Zhang Yaojun, Wei Zhaobin, Deng Cun, Xin Qin . Studies of dispersion state and catalytic activitiesof MoO₃/(TiO₂/SiO₂). J Mol Catal, 1996, 10(3): 207–212 (in Chinese)
17. Zhang Yufen, Xie Youchang, Xiao Nianhua, Han Wei, Tang Youqi . Effect of additive MgO and La₂O₃ on the nickel catalysts inmethanation. PetrolchemTechnol, 1985, 14(3): 141–146 (in Chinese)
18. Gui Linlin, Guo Qinlin, Xie Youchang, Tang Youqi . An investigationof the dispersion of CuCl on γ-Al₂O₃ surface and the adsorption of ethylene on CuCl/γ-Al₂O₃ and other supported transitionmetal salts. Scientia Sinica (Series B), 1984, 27(5): 445–455
19. Zhao Biying, Wu Nianzu, Gui Linlin, Zhang Lei, Bai Jingbin, Xie Youchang, Tang Youqi . Studies of the dispersionfor Zinc oxide on the surface of the silica gel and the surface acidityof ZnO/SiO₂. ScientiaSinica (Series B), 1985, (10): 891–897
20. Deng Cun, Duan Lianyun, Xu Xianping, Wu Nianzu, Xie Youchang . The monolayer dispersion state of TiO₂ on the surface of γ-Al₂O₃. J Mol Catal, 1992, 6(5): 394–397 (in Chinese)
21. Wei Zhaobin, Xin Qin, Sham E L, Grange P, Delmon B . Studies of TiO₂ distribution over Al₂O₃ by AEM. Acta Phys Chem Sin, 1990, 6(4): 474–479 (in Chinese)
22. Deng Cun, Liang Junfang, Zeng Yucai . Effects of reparation method on the reforming activityof nickel catalysts. Natur Gas Chem Ind, 2002, 27(1): 4–8 (in Chinese)
23. Deng Cun, Zhou Zhenhua, Tong Xun . Effect of TiO₂-modified γ-Al₂O₃ on the catalytic behaviorof MoO₃/γ-Al₂O₃ and CoO-MoO₃/γ-Al₂O₃. J Mol Catal, 1998, 12(2): 107–112 (in Chinese)