Kinetics study of positronium o-Ps on MoNi/Al2O3 hydrotreating catalyst by PASCA

The reaction kinetics of positronium o-Ps on MoNi/Al2O3 hydrotreating catalyst was studied by using the positron annihilation spectroscopy for chemical analysis (PASCA). It was known from the experimental results that, under the temperature range of 20-100°C and vacuum 1 × 10-5 Pa, the activation energy of o-Ps on MoNi/Al2O3 catalyst was 11.09 kJ/mol, reaction frequency factor A was 1.178 × 1010 kg/ (mol · s) and reaction rate constant K was 1.344 × 108 kg/ (mol · s) (25°C), respectively, on the basis of which, the kinetic equation was set up. The experiments were also carried out for the catalysts with various metal loading on the same support, and it was found that the characteristic correlative coefficient (k) is only related with the characteristics of support, but had nothing to do with the kinds of loading metals. The change of MSI could be shown by the change of k, to give some inspiration to the development of better catalyst.