Stability and dissolution kinetics of Pd/MCM-41

Abstract

The stability of Pd impregnated MCM-41 (Pd/MCM-41) at mass per cent loadings of Pd of 0.12 and 1.2% was investigated over 50 days. Results showed that the silica in Pd/MCM-41 dissolves at a lower rate than in pure MCM-41 and is likely metastable with respect to amorphous silica. Dissolution rates were lower at a higher mass per cent loading of Pd. Simulations of Pd/MCM-41 dissolution kinetics made using Phreeqci indicated log dissolution rate constants of −12.7 and −12.9 for 0.12 and 1.2% Pd/MCM-41, respectively.

Keywords:

• Phreeqc
• Metastability
• Mesoporous
• MCM-41
• Silica
• Degradation
• Porous
• Kinetics