Structures and catalytic properties of magnesium molybdate in the oxidative dehydrogenation of alkanes |
| |
Authors: | YS Yoon K Suzuki T Hayakawa S Hamakawa T Shishido K Takehira |
| |
Affiliation: | (1) Chemical Technology Division, Institute of Research and Innovation, 1201 Takada, Kashiwashi, Chiba, 277, Japan;(2) Department of Surface Chemistry, National Institute of Materials and Chemical Research, 1-1 Higashi, Tsukuba-shi, Ibaraki, 305, Japan;(3) Department of Applied Chemistry, Hiroshima University, 1-4-1 Kagamiyama, Higashihiroshima, 739, Japan |
| |
Abstract: | Magnesium molybdates have been prepared from an aqueous solution of magnesium nitrate and ammonium paramolybdate under various pH conditions and used for the selective oxidation of propane and isobutane with gaseous oxygen under atmospheric pressure in the temperature range of 360–520°C. The structure analyses by XRD and FT-IR showed the formation of three phases, -MgMoO4, -MgMoO4 and Mg2Mo3O11, in the catalysts calcined below 550°C. The catalyst prepared at pH=5.7 showed the highest activity for the oxidative dehydrogenation of the alkanes as well as the strongest acidity. By XPS measurements, an excess amount of Mo compared to Mg was observed over the active catalysts. It is likely that the excess molybdenum species is present as molybdate and creates acidic sites over the catalyst surface. |
| |
Keywords: | magnesium molybdates catalyst preparation pH conditions selective oxidation propane isobutane acidic properties |
本文献已被 SpringerLink 等数据库收录! |
|