| Popis: |
Selective partial oxidation of methane to methanol was investigated over Cu-ZSM-5 with two main objectives: to improve catalytic activity through modification of the catalyst surface; and to work towards a low-temperature, gas phase catalytic process through building an understanding of the catalytic cycle. Na-ZSM-5 was modified by the commercial silylating agent BSTFA, synthesising a range of functionalised catalysts from 0.2-20% silylation by weight. Successful silylation was confirmed by DRIFTS. Following aqueous copper exchange td form functionalised Cu-ZSM-5, analysis by BET and transmission IR revealed selective exchange of catalytically active copper in the zeolite channels at 1-2% silylation, with reduced exchange of inactive copper on the external surface. The latter was also observed during TEM. A large increase in catalytic activity was determined by TPO-MS analysis. Silylation was therefore used to increase the proportion of catalytically active copper present, with potential application in the synthesis of more active catalysts. |
