Hydrodeoxygenation of glycerol with in situH₂ formation over Pt catalysts supported on Fe modified Al₂O₃: effect of Fe loading

Abstract

BACKGROUND: Glycerol hydrodeoxygenation to 1,2-propanediol is a reaction of commercial and environmental significance. However, the need for hydrogen supply is a main drawback of the process. This study aims at the development of effective catalysts for glycerol hydrodeoxygenation with in situ H 2 formed. Pt/Al 2 O 3 and Pt/Fe 2 O 3 -Al 2 O 3 catalysts with different Fe/Pt ratios were synthesized and evaluated. N 2 physisorption, XRD, TPR-H 2 , TGA and DRIFTS-CO characterization techniques were used. Main focus was given on catalyst reusability, while a parametric study was also performed. RESULTS: Fe addition promotes catalysts activity. Characterization showed that there is an electron interaction between Pt andFe which is responsible for this enhancement. However, Fe/Pt ratio and reduction temperature affect catalyst performance. The increase of Fe loading leads to lower H 2 formation rates but also to more stable catalyst performance. The most promising results were achieved over the Fe richer catalyst which exhibited 51.5% 1,2-propanediol selectivity, 93.8% glycerol conversion, under 3.5 MPa N 2 , at 250 ∘ C, 1 h and pre-reduction at 200 ∘ C. CONCLUSION:The presence of Fe in Pt/Al 2 O 3 catalysts was proved decisive for the combined cycle of glycerol hydrodeoxygenation-aqueous phase reforming. The high activity and the stable performance in aqueous medium may render these materials as suitable catalysts for various liquid phase hydrodeoxygenation reactions.

Liquid Phase Hydrogenation of MIBK over M/CsPW (M = Ag, Ru, Pt, and Pd)

“…However, more experiments are needed to explore the conversion % in a temperature higher than 443 K. However, H2 pressure optimization showed that the best MIBK conversion was achieved at 10 atm, while at H2 pressure = 15 the obtained conversion decreased. This can be explained by to the blocking of the active sites at high H2 pressure, as reported by Lemonidou and co-workers [24], and Holles and co-workers [25].…”

Catalytic Transfer Hydrogenation of Biomass‐Derived Substrates to Value‐Added Chemicals on Dual‐Function Catalysts: Opportunities and Challenges

“…The role of Fe 3+ species as a promoter for bifunctional catalysts is largely unexplored. In another study, Lemonidou and co‐workers studied the influence of Fe 3+ loading on the surface acidity of an Al 2 O 3 support and promotional effects for CTH‐II of glycerol in the presence of Pt catalysts . Strong interactions between Fe 2 O 3 and Al 2 O 3 phases lower the crystal size of the latter species.…”

“…In another study,L emonidou and co-workerss tudied the influence of Fe 3 + loading on the surface acidity of an Al 2 O 3 support and promotional effects forC TH-II of glycerol in the presence of Pt catalysts. [46] Strong interactions between Fe 2 O 3 and Al 2 O 3 phases lower the crystal size of the latter species. With increasing Fe loading, characterization by means of diffuse reflectance IR Fourier transform spectroscopy (DRIFTS) indicates that the electron density of Pt increases, although the effect of such electron-transfer behavior from Fe to Pt of ab ifunctional nature is still not correlated with experimental data in this work.…”

In Focus: Catalytic Transformation of Biomass to Chemicals

“…This issue of the Journal of Chemical Technology and Biotechnology (JCTB) includes 8 research articles that deal with catalytic oxidation, hydrodeoxygenation, oxidative esterification, epoxidation/ring‐opening/polymerisation and hydrogenation of bio‐sourced reactants.…”

“…Iron as a promotor in glycerol hydrodeoxygenation (to 1,2‐propanediol) over Pt/Al 2 O 3 was considered by Yfanti et al . . Incorporation of Fe served to increase catalytic activity, which is linked to Fe→Pt electron transfer.…”