Mesoscale combustion of ethanol and dimethyl ether over Pt/ZSM-5: Differences in combustion characteristics and catalyst deactivation

摘要

The combustion of ethanol and dimethyl ether (DME) was performed over Pt/ZSM-5 catalyst in a packed-bed reactor to investigate the combustion characteristics and catalyst deactivation. Results showed that the CO2 yield and wall temperature for the combustion of DME were higher than those for the combustion of ethanol. The maximum CO2 yield for both fuels surpassed 72%. After 48 h of continuous combustion, CO2 yields of DME and ethanol decreased by 13.8% and 38.9%, respectively, attributed to the agglomeration of Pt and the formation of carbonaceous deposits on the catalyst. Transmission electron microscopy images showed considerable Pt agglomeration after ethanol combustion. Temperature-programmed oxidation results revealed two types of carbonaceous deposits with oxidation temperatures of 225 and 345 degrees C after DME combustion, but only the former type was detected after ethanol combustion. X-ray photoelectron spectra revealed that the mainly increased surface carbonaceous species were C-C/C-H and O-C=O after the combustion of ethanol and DME, respectively. (C) 2015 Elsevier Ltd. All rights reserved.