Volume 1, Issue 1, Pages 178-199 (September 2017) Hydrodeoxygenation of Sorbitol to Monofunctional Fuel Precursors over Co/TiO2  Nathaniel M. Eagan, Joseph P. Chada, Ashley M. Wittrig, J. Scott Buchanan, James A. Dumesic, George W. Huber  Joule  Volume 1, Issue 1, Pages 178-199 (September 2017) DOI: 10.1016/j.joule.2017.07.004 Copyright © 2017 Elsevier Inc. Terms and Conditions

Joule 2017 1, 178-199DOI: (10.1016/j.joule.2017.07.004) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 1 Generalized Pathway for the Production of Monofunctional Species from Sorbitol APHDO Sorbitol is initially converted to higher oxygenates either through acid-catalyzed dehydrations or metal-promoted retro-aldol condensation. Subsequently these species are deoxygenated via a combination of several reactions including hydrogenation, dehydrogenation, dehydration, ring-rearrangement reactions, and decarbonylation, which require both metal and acid functionalities. CO is converted to CO2 via water-gas shift (WGS) or reduced to CH4. The present study additionally provides evidence for the coupling of higher oxygenates to oligomers, which may then either degrade to humins and coke or fragment into monofunctionals. Controlled deoxygenation of higher oxygenates produces monofunctional species prior to full deoxygenation to alkanes. Joule 2017 1, 178-199DOI: (10.1016/j.joule.2017.07.004) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 2 Production of Monofunctional Species in the APHDO of Sorbitol over Co/TiO2 versus TOS at Multiple WHSVs (A–D) Reactions performed at WHSVs of (A) 0.35 hr−1, (B) 0.70 hr−1, (C) 1.40 hr−1, and (D) 2.80 hr−1. Other conditions: 541 K, 6.31 MPa H2 at 40 mL/min, 3.30 g of catalyst. Joule 2017 1, 178-199DOI: (10.1016/j.joule.2017.07.004) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 3 Production of Various Categories of Species as a Function of 1/WHSV (A and B) Yields are reported for each WHSV at (A) an early time on stream (∼16 turnovers) and (B) a later time on stream (∼34 turnovers). Turnover is calculated as the mass of feed passed over the catalyst per mass of catalyst. Conditions: 541 K, 6.31 MPa H2 at 40 mL/min, 3.30 g of catalyst, WHSV = 0.35–2.80 hr−1. Joule 2017 1, 178-199DOI: (10.1016/j.joule.2017.07.004) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 4 Distribution of Monofunctionals between Co/TiO2 and Catalysts from Literature Co/TiO2 data at 0.70 hr−1. Pt/Zr-P and Pt-ReOx/C data provided at conditions for maximum MF yield from Kim et al.12 Joule 2017 1, 178-199DOI: (10.1016/j.joule.2017.07.004) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 5 Selectivity to Species of Different Carbon Lengths over Co/TiO2, Pt/Zr-P, and Pt-ReOx/C (A) Overall product distribution. (B) Selectivity within the monofunctionals produced. Co/TiO2 data at 0.70 hr−1. Pt/Zr-P and Pt-ReOx/C data provided at conditions for maximum MF yield from Kim et al.12 Joule 2017 1, 178-199DOI: (10.1016/j.joule.2017.07.004) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 6 FT-ICR MS Spectra for Aqueous Fraction of APHDO Products at 2.80 hr−1 after 34 Turnovers (A) Oxygen number versus carbon number. (B) Double-bond equivalence versus carbon number. Joule 2017 1, 178-199DOI: (10.1016/j.joule.2017.07.004) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 7 FT-ICR MS Spectra for Aqueous Fraction of APHDO Products (A–F) Oxygen number versus carbon number is shown at WHSVs of (A) 1.40 hr−1, (C) 0.70 hr−1, and (E) 0.35 hr−1. Corresponding plots for double-bond equivalence versus carbon number are also shown at the same WHSVs: (B) 1.40 hr−1, (D) 0.70 hr−1, and (F) 0.35 hr−1. The maximum intensity for these plots is based on the maximum observed at 1.40 hr−1. Joule 2017 1, 178-199DOI: (10.1016/j.joule.2017.07.004) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 8 Equilibrium Vaporization of Water under APHDO Conditions Conditions modeled: 20 wt% glucose in water cofed with 40 mL/min (STP) H2 at 6.31 MPa into a flash tank operating at various temperatures with the liquid flow rates used in this study. Joule 2017 1, 178-199DOI: (10.1016/j.joule.2017.07.004) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 9 XRD Patterns of Support, Pretreated Catalysts, and Spent Catalysts An asterisk indicates the location of an observable Co3O4 peak. Joule 2017 1, 178-199DOI: (10.1016/j.joule.2017.07.004) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 10 XRD Patterns in Co3O4 Regime Data fits are shown by dotted lines. Joule 2017 1, 178-199DOI: (10.1016/j.joule.2017.07.004) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 11 Representative STEM Images of Catalysts (A–C) (A) Prior to reaction, (B) after reaction at 0.70 hr−1, and (C) after reaction at 2.80 hr−1. The particle circled in (C) appears to be Co due to its higher contrast relative to similarly sized TiO2 particles. Joule 2017 1, 178-199DOI: (10.1016/j.joule.2017.07.004) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 12 Comparison of Production Distribution from APHDO of Sorbitol over Co/TiO2 with Catalysts from Literature Data provided at conditions for maximum MF yield from the following sources: Pd-Ag/WOx-ZrO2,37 Pt/ZrO2 + WOx/Al2O,16 Pt-ReOx/TiO2,20 Pt-Nb/ZrCr,21 Pt/Zr-P,12 and Pt-ReOx/C.12 Joule 2017 1, 178-199DOI: (10.1016/j.joule.2017.07.004) Copyright © 2017 Elsevier Inc. Terms and Conditions