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

Abstract

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 °C and 1 atm, while the regeneration of the catalyst was performed with an air flow at 500 °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, CAr–OH, and multiple C−C hydrogenolyses, while the Fe and Pd–Fe principally catalyzed the CAr–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.

Construction of a highly active and water-resistant Ni-based catalyst for the HDO reaction of phenol

“…8,9 The development of highly active catalysts for HDO technology is an important factor but still remains a great challenge. Many kinds of catalysts, such as noble metal catalysts, [10][11][12] metal sulde catalysts, 13,14 metal carbide catalysts 15,16 and transition metal catalysts [17][18][19] are widely used. However, noble metal catalysts are not appropriate for industrial utilization because of their high price, difficult availability, poor reusability and easy deactivation caused by carbon deposition.…”

Guaiacol Hydrodeoxygenation and Hydrogenation over Bimetallic Pt-M (Nb, W, Zr)/KIT-6 Catalysts with Tunable Acidity

“…30 Pd−Co and Pd−Fe supported on Al-MCM-41 were also reported for atmospheric guaiacol HDO at ∼400 °C, with the yield of fully deoxygenated products being <20%. 31 Pd−Fe was superior in activity, stability, and regeneration ability compared to Pd−Co. Ni/H-USY catalysts doped with Fe, Ga, Ce, La, or Sm were investigated for gas-phase HDO of guaiacol at 350 °C and atmospheric H 2 pressure, yielding <10% of fully deoxygenated products.…”

“…Bimetallic Ni-Re/SiO 2 catalyst showed a higher guaiacol HDO activity compared to monometallic (Ni, Re, Cu, Co) and other bimetallic (Cu–Re and Co–Re) catalysts, yielding cyclohexane as the major product at 250 °C and at 3 MPa H 2 pressure . Pd–Co and Pd–Fe supported on Al-MCM-41 were also reported for atmospheric guaiacol HDO at ∼400 °C, with the yield of fully deoxygenated products being <20% . Pd–Fe was superior in activity, stability, and regeneration ability compared to Pd–Co.…”

Special Issue “Metal Nanoparticles as Catalysts for Green Applications”

“…In fact, most of the papers deal with reactions for biomass valorization, covering a wide range of applications, which highlights the versatility of the subject matter. For instance, guaiacol has been upgraded by hydrodeoxygenation [2], glucose by aqueous phase reforming [3], 5-hydroxymethylfurfural (HMF) by selective oxidation [4], and ethanol by steam reforming [5].…”

“…On the topic of biomasses valorization, the paper by Nga Tran et al [2] investigates the hydrodeoxygenation of guaiacol over Pd-Co and Pd-Fe catalysts supported on Al-MCM-41, with a focus on stability and regeneration, which are of great importance in bio-oil upgrading. The authors found that the bimetallic Pd-Co and Pd-Fe showed a higher yield and stability than monometallic Co and Fe, since the coke formation was reduced.…”