Zhaohua Luan;东元 赵;Larry Kevan
University of Houston;China Association for Science and Technology
发表时间:1998-2
期 刊:Microporous and Mesoporous Materials
语 言:English
U R L: http://www.scopus.com/inward/record.url?scp=0031995993&partnerID=8YFLogxK
A series of aluminophosphate materials without (UHM-1) and with variable amounts of vanadium (VUHM-1) have been synthesized in the presence of a cationic surfactant cetyltrimethylammonium chloride and an organic base tetramethylammonium hydroxide. Powder X-ray diffraction and electron probe microanalysis show that both UHM-1 and VUHM-1 with V/A1 ratios up to 0.05 possess disordered arrays of tubular channels which mimic the hexagonal MCM-41 structure. The overall P/A1 ratio is about half of the initial unity ratio in the gel mixture, especially for VUHM-1. This indicates incomplete condensation of phosphorus oxide and a non-ideal aluminophosphate framework; this seems associated with poorer thermal stability than microporous aluminophosphate and mesoporous aluminosilicatc MCM-41. Electron spin resonance and diffuse reflectance ultraviolet-visible spectroscopies reveal that in as-synthesized VUHM-1 the vanadium exists as monoatomically dispersed square pyramidal VO2+ ions and as tetrahedral V5+ ions which are consistent with a framework location for the vanadium.
Scopus度量
年份 | CiteScore | SJR | SNIP |
---|---|---|---|
1996 | |||
1997 | |||
1998 | |||
1999 | 0.591 | 1.06 | |
2000 | 0.983 | 1.367 | |
2001 | 1.493 | 1.378 | |
2002 | 1.869 | 1.338 | |
2003 | 1.607 | 1.511 | |
2004 | 1.344 | 1.632 | |
2005 | 1.408 | 1.766 | |
2006 | 1.51 | 1.32 | |
2007 | 1.392 | 1.235 | |
2008 | 1.373 | 1.444 | |
2009 | 1.25 | 1.331 | |
2010 | 1.551 | 1.404 | |
2011 | 6.6 | 1.524 | 1.464 |
2012 | 5.8 | 1.496 | 1.554 |
2013 | 5.4 | 1.234 | 1.349 |
2014 | 5.8 | 1.25 | 1.277 |
2015 | 6.6 | 1.184 | 1.167 |
2016 | 6.1 | 1.093 | 1.209 |
2017 | 6.4 | 1.08 | 1.107 |
2018 | 7 | 1.066 | 1.224 |
2019 | 7.7 | 0.999 | 1.256 |
2020 | 7.1 |
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