Selective hydrogenation of bromonitrobenzenes over Pt/γ-Fe2O3

✍ Scribed by Xiaodong Wang; Minghui Liang; Hongquan Liu; Yuan Wang

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 838 KB
• Volume: 273
• Category: Article
• ISSN: 1381-1169
• DOI: 10.1016/j.molcata.2007.04.004

✦ Synopsis

The Pt/␥-Fe 2 O 3 nanocomposite catalyst exhibited high catalytic activities and superior selectivities to ortho-bromoaniline (o-BAN), metabromoaniline (m-BAN) and para-bromoaniline (p-BAN) in the hydrogenation of ortho-bromonitrobenzene (o-BNB), meta-bromonitrobenzene (m-BNB) and para-bromonitrobenzene (p-BNB), respectively. The hydrodebromination of bromoanilines (BANs) over the Pt/␥-Fe 2 O 3 nanocomposite catalyst was fully suppressed even at complete conversion of the substrates for the first time. Elevating hydrogen pressure from 0.1 to 2.0 MPa could not only increase the hydrogenation rates of o-BNB, m-BNB and p-BNB by 8.8, 11.8 and 10.0 times, respectively, but also further improve the selectivities to o-BAN, m-BAN and p-BAN to a level higher than 99.9%. A new hydrodebromination pathway in the hydrogenation of bromonitrobenzenes (BNBs), i.e. through the hydrodebromination of the condensation intermediates was revealed.