The effect of propane activation over Ga-modified H-ZS M-5 catalysts

Article abstract of DOI:10.1002/recl.19941131009

In sity 13C MAS NMR was used to investigate the influence of total and partial pressure of propane on the initial stages of its conversion over a Ga/H-MFI catalyst. (2-13C) Propane was the labelled reactant.Different pressures were achieved by varying the amounts of propane and of nitrogen as diluent in the cell.The nature of primary and secondary labelled reaction products depends on total pressure.High total and partial pressures of propane enhance bimolecular primary formation of n-butane and isobutane via a BREST (Bifunctional Reaction Step) mechanism.Low total pressure leads to methane and polymeric fragments as primary products.A reaction pathway including the formation of a polymeric hydrocarbon-chain intermediate is proposed to account for secondary isobutane formation at low pressure.The influence of pressure on reaction equilibria and kinetics and on adsorption and exchange processes is discussed.