1. Role of poly(N-vinyl-2-pyrrolidone) in Ni dispersion for highly-dispersed Ni/SBA-15 catalyst and its catalytic performance in carbon dioxide reforming of methane.
- Author
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Yang, Weiwei and He, Dehua
- Subjects
- *
POVIDONE , *NICKEL catalysts , *DISPERSION (Chemistry) , *CARBON dioxide , *CATALYST supports , *METHANE - Abstract
A poly( N -vinyl-2-pyrrolidone) (PVP)-assisted wet impregnation method has been developed for preparing highly-dispersed supported Ni/SBA15-PVP (1/X) catalysts, in which 1/X indicates the molar ratio of PVP polymer to Ni. XRD and TEM results of as-prepared samples showed that PVP addition could dramatically promote the dispersion of NiO on SBA-15, with the n PVP /n Ni ratios in the range of 1/5000–1/1000. Whereas, severe sintering of NiO could be observed on Ni/SBA15-PVP (1/X) catalysts prepared with no PVP (1/X = 0), insufficient PVP (1/X = 1/7500) or superabundant PVP (1/X = 1/100). These catalysts were employed to catalyze the carbon dioxide reforming of methane (CRM) reaction, and the optimized Ni/SBA15-PVP (1/X) catalysts (1/X = 1/5000–1/1000) exhibited much better stability than others during the 25 h test. Besides, the role of PVP addition during the preparation process was illustrated detailedly with Raman, 1 H NMR, UV–vis, FTIR, and TPO characterizations. PVP would interact with Ni(NO 3 ) 2 . 6H 2 O to form complexes through the coordination of the oxygen and nitrogen atoms in the ring of PVP, with Ni 2+ , NO 3 − and H 2 O from the precursor during the drying step. Moreover, this complex could improve the stabilization, inhibit the redistribution and affect the decomposition behavior of the precursor, which ultimately led to a significantly improvement of the NiO dispersion on SBA-15 support. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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