Effect of boron addition on the active sites of Co-Mo(W)/Al_2O_3 catalysts

摘要

The effect of boron addition on the active sites of Co-Mo(W)/Al2O3 catalysts has been extensively investigated by means of a chemical vapor deposition (CVD) technique using Co(CO)3NO as a precursor of Co. The addition of boron weakened the interactions between molybdenum (tungsten) oxides and the A12O3 surface, leading to an increase in the intrinsic activity on the Co-Mo(W)-S structure, in a different way depending on the presulfidation temperature. The thermal stability of the Co-Mo-S structure depends on the support; the Co-Mo-S structure supported on A12O3 is thermally much more stable than that supported on B/Al_2O_3.