Ceria-Zirconia/Zeolite Bifunctional Catalyst for Highly Selective Conversion of Syngas into Aromatics

Ceria-zirconia solid solutions with tunable surface oxygen vacancy have been used in the direct conversion of syngas into aromatics after coupling with ZSM-5 zeolite. A high selectivity of 83.1% to aromatics has been achieved from syngas with low H-2/CO ratio over Ce0.2Zr0.8O2/ZSM-5 bifunctional catalyst. The surface oxygen vacancy of Ce0.2Zr0.8O2 is supposed to facilitate the formation of oxygenates which act as intermediates for C-C coupling and aromatization on ZSM-5, and thus contribute to the well kinetic matching between C-O activation and C-C coupling over these two components of catalyst. The ceria-zirconia with abundant surface oxygen vacancies and enhanced lattice oxygen mobility intimately mixed with ZSM-5 zeolite with moderate acidity and crystal size play an important role in the catalytic performance.