Hydrodeoxygenation of Guaiacol over Pd-Co and Pd-Fe Catalysts: Deactivation and Regeneration

In bio-oil upgrading, the activity and stability of the catalyst are of great importance for the catalytic hydrodeoxygenation (HDO) process. The vapor-phase HDO of guaiacol was investigated to clarify the activity, stability, and regeneration ability of Al-MCM-41 supported Pd, Co, and Fe catalysts in a fixed-bed reactor. The HDO experiment was conducted at 400 degrees C and 1 atm, while the regeneration of the catalyst was performed with an air flow at 500 degrees C for 240 min. TGA and XPS techniques were applied to study the coke deposit and metal oxide bond energy of the catalysts before and after HDO reaction. The Co and Pd-Co simultaneously catalyzed the CArO-CH3, C-Ar-OH, and multiple C-C hydrogenolyses, while the Fe and Pd-Fe principally catalyzed the C-Ar-OCH3 hydrogenolysis. The bimetallic Pd-Co and Pd-Fe showed a higher HDO yield and stability than monometallic Co and Fe, since the coke formation was reduced. The Pd-Fe catalyst presented a higher stability and regeneration ability than the Pd-Co catalyst, with consistent activity during three HDO cycles.

Automated summary

In this study, the activity and stability of different metal catalysts in vapor-phase HDO process were investigated, revealing that bimetallic Pd-Co and Pd-Fe catalysts showed higher HDO yield and stability compared to monometallic catalysts, with Pd-Fe catalyst demonstrating higher stability and regeneration ability.