Vapor phase catalytic degradation of bis(2-chloroethyl) ether on supported vanadia-titania catalyst

摘要

Series of V2O5-TiO2 catalysts with varying vanadium content are prepared by impregnation method. The catalyst composition is determined by XRD and Smart mapping (SEM-EDAX), respectively. The bulk reducibility of the catalyst is determined by the temperature programmed reduction (TPR). Catalyst activity and stability are elucidated in vapor phase catalytic degradation of bis(2-chloroethyI) ether (CEE). The factors affecting the process parameters such as gas hourly space velocity (GHSV), feed ratios, reaction temperature and vanadium content are studied for getting maximum degradation of CEE. Results reveal that vanadium content and reaction temperature have significant influence on the activity of catalyst, and the optimum vanadium content is identified for maximum degradation. The catalyst having monolayer coverage of vanadia (6% vanadium oxide) gave better performance for the degradation of CEE at 250 °C and the total oxidation is predominant above 200 °C. The GC-MS and ATD coupled GC-MS analyses reveal the degraded products are acetaldehyde, dihydrofurans, carbon dioxide, hydrochloric acid, trace amount of chloroacetaldehyde and chloroethanol, which confirms the proposed degradation path for total oxidation and partial oxidation. A 90% of CEE degradation is achieved at 300 °C and GHSV of 19,000 h~(-1) over 6 wt% of V2O5/TiO2. A plausible surface mechanism is proposed based on the analyses results.