Pd(II)-doped SiO2/Fe2O3 nanofibers as a novel catalyst for the ethanol dehydration reaction.

A synthetic technique based on electrospinning in conjunction with the sol–gel method and thermal treatment was employed to fabricate Pd(II)-doped SiO2/Fe2O3 nanofibers (NFs) with different Pd(II) doping amounts. These materials were evaluated for their catalytic ability in the ethanol dehydration reaction. Interestingly, the coexistence of the mixed-phase structure α-/γ-Fe2O3 indicates that the Pd(II) dopant inhibits the γ-Fe2O3-to-α-Fe2O3 phase transformation even under high-temperature thermal treatment. A higher reaction temperature is more beneficial to facilitate catalytic activity than a lower temperature. The catalytic reaction is improved upon adding Pd(II), probably due to the enhancement of the lattice oxygen mobility in the presence of Pd(II) in SiO2/Fe2O3. As the Pd(II) doping increases, the catalytic activity is gradually promoted. For 0.15 wt% Pd(II)-doped SiO2/Fe2O3 NFs produced at a reaction temperature of 670 °C, the ethanol conversion reaches a maximum value of 15.9%, and the selectivity of ethylene is 96.2%. It is inferred that a larger total proportion of active oxygen species, including lattice oxygen and surface chemisorbed oxygen, can better generate a strong catalytic reaction. [ABSTRACT FROM AUTHOR]