Release Time:2019-03-12  Hits:

Indexed by: Journal Article

Date of Publication: 2017-04-01

Journal: CHEMICAL ENGINEERING JOURNAL

Included Journals: EI、SCIE

Volume: 313

Page Number: 37-46

ISSN: 1385-8947

Key Words: Plasma chemistry; Hydrogen peroxide; Direct synthesis; Selectivity control; Electron density; Average electron energy

Abstract: Low selectivity is one of the key problems which limit the application of plasma in chemical fields. High selectivity and concentration of H2O2 are critical in the direct synthesis of H2O2. Herein, we report that the selectivity of the H-2/O-2 plasma reaction can be controlled by specific energy input (SEI), i.e. low SEI leads to high H2O2 selectivity. When the SEI was fixed at 2.08 j/ml, the H2O2 selectivity reached 91% with 17% O-2 conversion, and a H2O2 solution with high concentration (90 wt.%) was achieved. Plasma diagnostics and theoretical calculation results indicate that, low SEI results in low electron density, which leads to high H2O2 selectivity but low O-2 conversion. FurtherMore, the collision cross sections of H-2 and O-2 molecules with electrons indicate that the H-2/O-2 plasma, with average electron energy of 11.5 eV, can synthesize H2O2 with high selectivity and high O-2 conversidn. (C) 2016 Elsevier B.V. All rights reserved.