Design and Optimization of Carbon‐Based Bimetallic Catalysts for Catalytic Cracking of Tar Model Compounds

ABSTRACT

Biomass tar from pyrolysis restricts the practical engineering application of biomass gasification. Carbon‐based bimetallic Ni‐based catalysts modified by Cu and Co promoters were synthesized to boost catalytic performance for toluene cracking. Physicochemical characterizations under two preparation atmospheres reveal that Ni‐Cu and Ni‐Co alloys raise surface Ni° content and inhibit metal oxidation. Uniformly dispersed tiny metal particles also increase hydrogen concentration in product gas. Experimental results show that Ni4‐Cu1‐H delivers excellent low‐temperature activity at 600°C, while Ni4‐Co1‐H achieves a maximum hydrogen selectivity of 75% owing to smaller metal grains. Stability tests confirm Ni4‐Cu1‐H maintains the best activity after 300 min reaction. Comparative characterizations of fresh and spent catalysts clarify the anti‐deactivation mechanism of bimetallic catalysts: they suppress amorphous carbon graphitization and alter carbon deposition forms, thus slowing catalyst deactivation.