LOW-TEMPERATURE REDUCTION OF GALLIUM IN A GA2O3 HZSM-5 CATALYST

Several experiments were performed to provide convincing evidence for low temperature gallium reduction in a Ga2O3/HZSM-5 catalyst. XPS meas urements showed the appearance of a Ga(I) signal after in situ hydroge n reduction at temperatures ranging between 373 and 673 K. No transfer of reduced gallium species from Ga2O3 to the zeolite particles was de tected. A revision of the existing reduction mechanism is thus propose d. It is suggested here that the actual role of the HZSM-5 zeolite cou ld be to provide a kind of activated hydrogen able to reduce Ga2O3.