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Title: Enhanced Fe2O3 Reducibility via Surface Modification with Pd: Characterizing the Synergy within Pd/Fe Catalysts for Hydrodeoxygenation Reactions

The synergistic catalysis in the hydrodeoxygenation of phenolic compounds over a Pd/Fe bimetallic surface has been well established. However, the nature of this synergy is still in part a mystery. In this work, we used a combined experimental and theoretical approach to understand a potential function of the surface Pd in the reduction of Pd/Fe2O3. This function of Pd was investigated via the comparison of the reduction properties as well as other physicochemical properties of samples synthesized by the reduction of Fe2O3 nanoparticles with and without surface Pd. Temperature-programmed reduction studies demonstrated the remarkable facilitation of reduction by addition of Pd, evidenced by a 150 degrees C shift toward lower temperature of the reduction peak of Fe3+. From X-ray photoelectron spectroscopy and theoretical calculation results, the interaction between Pd and the Fe2O3 surface occurs through the exchange of electrons with both the surface Fe and O atoms. This bonding between the Pd and surface oxide elements causes the Pd to partially donate electrons to the oxide surface, making the surface electrons more delocalized. This electron delocalization stabilizes the reduced oxide surfaces, as suggested by the TPR results and theoretical prediction. Therefore, the stabilization of the reduced Fe surface as wellmore » as the facilitated water formation by introduction of Pd is expected to significantly contribute to the Pd-Fe synergy in hydrodeoxygenation catalysis.« less
Authors:
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Publication Date:
OSTI Identifier:
1194314
Report Number(s):
PNNL-SA-107930
47660; 47800; 47953; 48593; 46190; KC0302010
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: ACS Catalysis, 4(10):3381-3392
Research Org:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
bimetallic catalysts; biomass conversion; hydrodeoxygenation; Pd-Fe; density functional theory; oxide doping effects; enhanced oxide reduction; Environmental Molecular Sciences Laboratory