Active Site Formation in Phillips CrO3/SiOx Catalysts: A DFT Study

The objective of this study is to elucidate the most known mechanisms concerning active site formation of Phillips catalysts during the induction period. To this end, a model Cr(VI)/SiO2 compound was subjected into reduction process aided by either ethylene or triethylaluminium (TEAL) as dominant species in reaction medium. As a general result, we found that reduction process is happened more easily using TEAL than it aided by ethylene monomer. This finding is in good agreement with experimental data which implies that by using TEAL, the induction time of Cr(VI)/silica is usually eliminated