Fabricating Bifunctional Co−Al₂O₃@USY Catalyst via In‐Situ Growth Method for Mild Hydrodeoxygenation of Lignin to Naphthenes

Abstract

To enhance the catalytic activity and stability of metal catalysts in the hydrodeoxygenation of lignin derivatives into naphthenes, a bifunctional Co−Al2O3@USY catalyst was fabricated by the reduction of CoAl layered double hydroxide in‐situ grown on the USY zeolite. In the hydrodeoxygenation of guaiacol, a 100.0 % conversion with cyclohexane yield up to 93.6 % was achieved at 180 °C, 3 MPa for 4 h, which should be the hitherto lowest reaction temperature that has been reported over Co‐based metal catalysts. This catalyst was also relatively stable with 5 runs and exhibited excellent catalytic performance in the hydrodeoxygenation of other lignin model compounds and even real lignin feedstock into naphthenes. The high‐efficiency of Co−Al2O3@USY was attributed to the synergistic effect between well‐dispersed small Co nanoparticles and abundant acidic sites on the USY surface, while the outstanding stability was attributed to the anchoring effect of Al2O3 matrix to Co nanoparticles which avoided the leaching of Co species and particle agglomeration. This work provides a potential strategy for the design of an efficient and stable catalyst for lignin utilization.

Enhancing the Production of Phenolic Monomers from Reductive Catalytic Fractionation of Biomass over Catalyst of Ni–N-Doped Carbon

“…The high proportion of Ni 2+ was due to the rapid oxidation of highly active Ni-based catalysts in the air and the formation of passivation layers. 43 In addition, there was a positive shift in the Ni 0 binding energy of Ni/C f as compared to Ni/AC, which signified the enhanced metal−carrier interaction. 44 The acidic site in the catalyst played a critical role in affecting its catalytic activity.…”

“…Combined with the binding energy of Ni 2+ on 2p 3/2 , it can be speculated that Ni 2+ mainly existed in the form of Ni­(OH) 2 . The high proportion of Ni 2+ was due to the rapid oxidation of highly active Ni-based catalysts in the air and the formation of passivation layers . In addition, there was a positive shift in the Ni 0 binding energy of Ni/C f as compared to Ni/AC, which signified the enhanced metal–carrier interaction .…”