Study on the construction of char-supported NiFe-NiFe2O4 catalyst and its catalytic cracking mechanism of biomass tar under relative low temperature

Abstract

Biofuels or chemicals from biomass resources is a perfect substitute for fossil resources to achieve carbon neutrality. Gasification is an important approach to realize the high-value utilization of biomass, but tar is the bottleneck problem. Herein, a char-supported NiFe-NiFe2O4 catalyst was constructed to accomplish the efficient tar catalytic cracking at the relative low temperature. The evolution process of NiFe-NiFe2O4 hybrid active sites and composite char support with core–shell structure of catalyst was revealed. The optimized f600Fe-Ni@Char catalyst exhibited the high tar conversion efficiency of 92.54% at 600 °C. Meanwhile, the catalyst displayed the stable catalytic activity of approximately 80% after initial 3 cycles. The structure–property relationships of catalyst indicated that the superior catalytic behavior was ascribed to the protective effect of carbon nanofibers shell layer and the activation effect of NiFe-NiFe2O4 hybrid active sites. This work provided useful information on solving the bottleneck derived from tar for biomass gasification.