Mesoporous mixed oxides derived from pillared oxovanadates layered double hydroxides as new catalysts for the selective catalytic reduction of NO by NH3

The mixed oxides derived from pillared oxovanadates LDH and copper substitutes pillared oxovanadates LDH with mesoporous properties have been prepared, characterized and tested as new catalysts in the process of the selective catalytic reduction (SCR) of NO by NH3. The results show that these materials are efficient catalysts for reducing NO to N-2. The NO conversions are about 70-80% for an GHSV value equal to 414,000 h(-1). The selectivity towards N2O does not exceed 2% on the whole range of temperature studied, 200-500 degreesC though on the new catalysts ammonia oxidation occurs for temperatures above 430 degreesC. On comparision to a conventional and copper substitutes pillared oxovanadates layered double hydroxides are much more selective towards N-2 though exhibit a weaker activity in NO reduction. (C) 2003 Elsevier B.V. All rights reserved.