Impact of the Oxygen Defects and the Hydrogen Concentration on the Surface of Tetragonal and Monoclinic ZrO<sub>2</sub> on the Reduction Rates of Stearic Acid on Ni/ZrO<sub>2</sub>

Foraita, Sebastian; Fulton, John L.; Chase, Zizwe A.; Vjunov, Aleksei; Xu, Pinghong; Baráth, Eszter; Camaioni, Donald M.; Zhao, Chen; Lercher, Johannes A.

doi:10.1002/chem.201405312

Cited by 96 publications

(100 citation statements)

References 38 publications

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“…Oxygen is not believed to dissociate at as low as 350 °C on zirconia. That is implied by the results of Foraita et al [43] where temperature-programmed isotopic exchange of oxygen shows that oxygen is able to dissociate above 460 °C on monoclinic and above 500 °C on tetragonal zirconia. We believe that benzyl species is stabilized together with a superoxide surface species (O 2 -).…”

Section: Discussionmentioning

confidence: 76%

Toluene oxidation over ZrO2-based gasification gas clean-up catalysts: Part B. Kinetic modeling

Viinikainen

Kouva

Lehtonen

et al. 2016

Applied Catalysis B: Environmental

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Section: Discussionmentioning

confidence: 76%

Toluene oxidation over ZrO2-based gasification gas clean-up catalysts: Part B. Kinetic modeling

Viinikainen

Kouva

Lehtonen

et al. 2016

Applied Catalysis B: Environmental

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“…Thus, the monodenate propionates (C2H5COO*) are detected on m-ZrO2 and t-ZrO2, locating at 1590, 1417 cm −1 and 1597, 1414 cm −1 , respectively. Besides those, two kind bidentate propionates (*C2H5COO*) are observed on m-ZrO2 and t-ZrO2, including chelating bidentate propionates (1556, 1560 cm −1 ) and bridging bidentate propionates (1512, 1470 cm −1 ; 1511, 1470 cm −1 ) [5,16,47]. The peaks of 1597 and 1560 cm −1 on t-ZrO2 shift to the lower wavenumber on m-ZrO2 (1590 and 1556 cm −1 ), indicating the stronger adsorption of propionic acid on m-ZrO2.…”

Section: Drifts Study Of Propionic Acid and 3-pentanone Adsorption Onmentioning

confidence: 99%

Effect of Zirconia Polymorph on Vapor-Phase Ketonization of Propionic Acid

Ding

Zhao

2019

Catalysts

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Vapor-phase ketonization of propionic acid derived from biomass was studied at 300-375 • C over ZrO 2 with different zirconia polymorph. The tetragonal ZrO 2 (t-ZrO 2 ) are more active than monoclinic ZrO 2 (m-ZrO 2 ). The results of characterizations from X-ray diffraction (XRD) and Raman suggest m-ZrO 2 and t-ZrO 2 are synthesized by the solvothermal method. NH 3 and CO 2 temperature-programmed desorption (NH 3 -TPD and CO 2 -TPD) measurements show that there were more medium-strength Lewis acid base sites with lower coordination exposed on m-ZrO 2 relative to t-ZrO 2 , increasing the adsorption strength of propionic acid. The in situ DRIFTS (Diffuse reflectance infrared Fourier transform spectroscopy) of adsorbed propionic acid under ketonization reaction reveal that as the most abundant surface intermediates, the monodentate propionates are more active than bidentate propionates. In comparison with m-ZrO 2 , the t-ZrO 2 surface favors monodentate adsorption over bidentate adsorption. Additionally, the adsorption strength of monodentate propionate is weaker on t-ZrO 2 . These differences in adsorption configuration and adsorption strength of propionic acid are affected by the zirconia structure. The higher surface concentration and weaker adsorption strength of monodentate propionates contribute to the higher ketonization rate in the steady state.Catalysts 2019, 9, 768 2 of 15 coordination of Ti 4+ cations exposed on the surface. Stubenrauch et al. studied the reaction of formic acid and acetic acid on CeO 2 (111) and (100) surface [24]. On both surfaces, CH 2 CO was produced through acetic acid dehydration near 600 K. However, acetone was detected only on the (111) surface during acetic acid decomposition at 600 K. This result is different from that obtained by Kim et al., since Ce 4+ cations of (111) surface possess one vacancy relative to the Ce 4+ cations in the bulk. Wang et al. carried out ketonization of carboxylic acid on anatase and rutile TiO 2 , monoclinic and tetragonal ZrO 2 at 503-533 K [25,26]. They showed that the reaction activity of acetic acid was higher over anatase TiO 2 than that over rutile TiO 2 , and attributed that to the more reactive monodentate acetate present on anatase TiO 2 , whereas unreactive bidentate acetate was present on rutile TiO 2 . The effect of different nanocrystals (nanocubes, nanorods and nanopolyhedra) of CeO 2 on acetic acid ketonization was studied by Snell et al. at 503 K in the condensed phase and at 623 K in the vapor phase [27]. They found that the crystal of CeO 2 was disrupted in the condensed phase with the formation of metal carboxylate, whereas the bulk structure was maintained during the vapor phase reaction. They suggested that the morphology of CeO 2 did not have a critical influence on the reaction activity in the condensed and vapor phase. Although some work has been done on the influence of the structure, no consensus has been reached. This may be due to the different reaction conditions (condensed phase and vapor phase) via the different reaction...

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“…For instance, Foraita et al. reported that the HDO of guaiacol proceeds efficiently on oxygen vacancies in catalysts . Prasomsri et al.…”

Section: Introductionmentioning

confidence: 99%

Synergetic Catalysis of Nickel Oxides with Oxygen Vacancies and Nickel Phosphide for the Highly Efficient Hydrodeoxygenation of Phenolic Compounds

Zhao

Chen

et al. 2018

ChemCatChem

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The highly efficient hydrodeoxygenation of oxygenated chemicals at a low temperature is a critical issue for biomass crude oil upgrading to reduce equipment and operation expense. The unique electronic features of oxygen vacancies have been found to facilitate deoxygenation above 250 °C. In this work, a series of NiOx/SiO2 catalysts that contain oxygen vacancies was prepared by a sol–gel and controllable temperature‐programmed reduction method. Results show that NiOx/SiO2 has a superior phenol hydrogenation activity in deoxygenation even at 180 °C to Ni2P/SiO2. The high hydrogenation activity derives from the flat adsorption of phenolics over low‐valence Ni cations induced by connected oxygen vacancies. After the introduction of NiOx into Ni2P catalysts, composite NiOx‐Ni2P/SiO2 (0.43≤x<1) bifunctional catalysts demonstrate better phenol hydrodeoxygenation performances under mild reaction conditions in comparison with individual Ni2P and NiOx catalysts and most catalysts presented previously because the coexistence of oxygen vacancies from NiOx and the acidity induced by Ni2P results in the synergistic effect of the adsorption configuration and hydrodeoxygenation ability. Besides, this composite catalyst also has a high activity for the hydrodeoxygenation of different bio‐derived cresol isomers. The reuse test results confirm that oxygen vacancies are relatively stable in comparison with the phosphide.

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Impact of the Oxygen Defects and the Hydrogen Concentration on the Surface of Tetragonal and Monoclinic ZrO₂ on the Reduction Rates of Stearic Acid on Ni/ZrO₂

Cited by 96 publications

References 38 publications

Toluene oxidation over ZrO2-based gasification gas clean-up catalysts: Part B. Kinetic modeling

Toluene oxidation over ZrO2-based gasification gas clean-up catalysts: Part B. Kinetic modeling

Effect of Zirconia Polymorph on Vapor-Phase Ketonization of Propionic Acid

Synergetic Catalysis of Nickel Oxides with Oxygen Vacancies and Nickel Phosphide for the Highly Efficient Hydrodeoxygenation of Phenolic Compounds

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Impact of the Oxygen Defects and the Hydrogen Concentration on the Surface of Tetragonal and Monoclinic ZrO2 on the Reduction Rates of Stearic Acid on Ni/ZrO2

Cited by 96 publications

References 38 publications

Toluene oxidation over ZrO2-based gasification gas clean-up catalysts: Part B. Kinetic modeling

Toluene oxidation over ZrO2-based gasification gas clean-up catalysts: Part B. Kinetic modeling

Effect of Zirconia Polymorph on Vapor-Phase Ketonization of Propionic Acid

Synergetic Catalysis of Nickel Oxides with Oxygen Vacancies and Nickel Phosphide for the Highly Efficient Hydrodeoxygenation of Phenolic Compounds

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Impact of the Oxygen Defects and the Hydrogen Concentration on the Surface of Tetragonal and Monoclinic ZrO₂ on the Reduction Rates of Stearic Acid on Ni/ZrO₂