Effects of zirconia phase on the synthesis of higher alcohols over zirconia and modified zirconia

He, Dekui; Ding, Yunjie; Luo, Hong-Yuan; Li, Can

doi:10.1016/s1381-1169(03)00542-9

Cited by 80 publications

(45 citation statements)

References 22 publications

(16 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the relative amount of Pd 3 Zr increases slightly with respect to Pd 2 Zr. This is also understandable on the basis of the Pd-Zr phase diagram: Pd 3 Zr is the thermodynamically most stable compound in the Pd-Zr system [25], with the system most likely approaching structural equilibrium. No oxidized bulk ZrO 2 species have also been observed in XRD after MSR, in contrast to Cu-Zr [18].…”

Section: Methanol Steam Reforming On the Pd-zr Bulk Samplementioning

confidence: 98%

“…ZrO 2 -containing catalysts have evoked recent interest both as additives to other catalytic systems and as isolated entities as well as for their ability to improve the structural integrity of various catalysts and to induce beneficial steering of reaction pathways to increase the respective selectivity of especially the methanol steam reforming (MSR) and methanol synthesis reactions [1][2][3][4][5][6]. Particularly rewarding in this respect is to focus on the Cu-ZrO 2 system, where the addition of ZrO 2 to the industrially the discussion.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A Comparative Discussion of the Catalytic Activity and CO2-Selectivity of Cu-Zr and Pd-Zr (Intermetallic) Compounds in Methanol Steam Reforming

et al. 2017

View full text Add to dashboard Cite

Abstract:The activation and catalytic performance of two representative Zr-containing intermetallic systems, namely Cu-Zr and Pd-Zr, have been comparatively studied operando using methanol steam reforming (MSR) as test reaction. Using an inverse surface science and bulk model catalyst approach, we monitored the transition of the initial metal/intermetallic compound structures into the eventual active and CO 2 -selective states upon contact to the methanol steam reforming mixture. For Cu-Zr, selected nominal stoichiometries ranging from Cu:Zr = 9:2 over 2:1 to 1:2 have been prepared by mixing the respective amounts of metallic Cu and Zr to yield different Cu-Zr bulk phases as initial catalyst structures. In addition, the methanol steam reforming performance of two Pd-Zr systems, that is, a bulk system with a nominal Pd:Zr = 2:1 stoichiometry and an inverse model system consisting of CVD-grown ZrO x H y layers on a polycrystalline Pd foil, has been comparatively assessed. While the CO 2 -selectivity and the overall catalytic performance of the Cu-Zr system is promising due to operando formation of a catalytically beneficial Cu-ZrO 2 interface, the case for Pd-Zr is different. For both Pd-Zr systems, the low-temperature coking tendency, the high water-activation temperature and the CO 2 -selectivity spoiling inverse WGS reaction limit the use of the Pd-Zr systems for selective MSR applications, although alloying of Pd with Zr opens water activation channels to increase the CO 2 selectivity.

show abstract

Section: Methanol Steam Reforming On the Pd-zr Bulk Samplementioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

A Comparative Discussion of the Catalytic Activity and CO2-Selectivity of Cu-Zr and Pd-Zr (Intermetallic) Compounds in Methanol Steam Reforming

et al. 2017

View full text Add to dashboard Cite

show abstract

“…c-ZrO2 is applied in oxygen sensors, t-ZrO2 is used as high performance transformation-toughened ceramics and can catalyze ethanol formation from syngas, while m-ZrO2 will catalyze isobutanol formation from syngas and is important for gate dielectrics and bioactive coatings. [1][2][3][4][5][6][7][8][9] The tetragonal and cubic phase are not stable at room temperature under thermodynamic equilibrium, but they can be stabilized via the incorporation of divalent and trivalent cations (Mg 2+ , Ca 2+ …). 10,11 Reducing the crystallite size of ZrO2 below 30 nm can have the same effect.…”

Section: Introductionmentioning

confidence: 99%

Fast and Tunable Synthesis of ZrO₂ Nanocrystals: Mechanistic Insights into Precursor Dependence

Keukeleere¹,

Roo

Lommens³

et al. 2015

Inorg. Chem.

View full text Add to dashboard Cite

ABSTRACT:In this work, ZrO2 nanocrystals (NCs) are synthesized via a solvothermal treatment in benzyl alcohol, which is an established method for the synthesis of many metal oxide nanocrystals. We found that the use of microwave heating allows for a reduction in reaction time from 2 days in the autoclave to merely 4 hours in the microwave. Furthermore, we were able to tune the crystallographic phase from pure cubic to pure monoclinic zirconia by changing the reaction mechanism through the use of a different zirconium precursor. Via GC-MS measurements we found that the release of a strong acid during synthesis controls the key mechanism behind the control over crystal phase formation. The as-synthesized ZrO2 NCs (cubic or monoclinic) are small in size (3 -10 nm), yet aggregated. However, aggregrate-free NCs are generated through a surface-functionalization with carboxylic acid ligands, providing stabilization in apolar solvents via steric hindrance. Solution 1 H NMR was used to study the details of this post-modification step and the surface chemistry of the resulting aggregate-free NCs. This led to the conclusion that not only a different crystal structure but also a different surface chemistry is obtained depending on the precursor composition.

show abstract

“…As the content of base sites increases, methyl formate is formed. Activity in dimethyl carbonate synthesis is exhibited only by samples in which the basicity is higher than the acidity or close to it.In recent years, there has been increased interest in using zirconium oxide and its stabilized forms in various catalytic processes [1][2][3], which is connected with their physicochemical characteristics and in particular with their acid-base properties.Back in 1985, Tanabe et al established that the behavior of ZrO 2 in catalysis is different depending on its calcination temperature. Zirconium dioxide calcined at 600°C exhibits the maximum activity relative to the reaction of hydrogenation of 1,3-butadiene, while a sample calcined at 800°C exhibits maximum activity relative to hydrogenation of cyclohexadiene [4].…”

mentioning

confidence: 99%

“…In recent years, there has been increased interest in using zirconium oxide and its stabilized forms in various catalytic processes [1][2][3], which is connected with their physicochemical characteristics and in particular with their acid-base properties.…”

mentioning

confidence: 99%

Effect of acid–base characteristics of ZrO2–Y2O3 on catalytic properties in carboxylation of methanol

2009

View full text Add to dashboard Cite

We have established that the calcination temperature for ZrO 2 -Y 2 O 3 catalysts changes their acid-base spectrum, which determines the direction of the conversions in the mixture MeOH + CO 2 . For samples with predominance of acid sites, the major product is dimethyl ether. As the content of base sites increases, methyl formate is formed. Activity in dimethyl carbonate synthesis is exhibited only by samples in which the basicity is higher than the acidity or close to it.In recent years, there has been increased interest in using zirconium oxide and its stabilized forms in various catalytic processes [1][2][3], which is connected with their physicochemical characteristics and in particular with their acid-base properties.Back in 1985, Tanabe et al. established that the behavior of ZrO 2 in catalysis is different depending on its calcination temperature. Zirconium dioxide calcined at 600°C exhibits the maximum activity relative to the reaction of hydrogenation of 1,3-butadiene, while a sample calcined at 800°C exhibits maximum activity relative to hydrogenation of cyclohexadiene [4]. The catalytic activity of zirconium oxide is due to the presence of both base and acid sites on its surface, which makes materials based on zirconium oxide promising for use in processes of heterogeneous acid-base catalysis occurring with participation of acid and base sites on the surface [5].One such process is the reaction of carboxylation of methanol, obtaining dimethyl carbonate (DMC), a valuable chemical product and a promising high-octane additive to motor fuels [6]. The prospects for this method for obtaining DMC involve the use of CO 2 , which is considered the main source of the "greenhouse effect" and causes global climate change [7]. The first studies of this reaction were conducted in the 1980s [8]. Only a few papers have been devoted to study of the reaction of methanol carboxylation in the presence of ZrO 2 [9, 10]. The metastable tetragonal modification t-ZrO 2 may be of special interest; stabilization of the latter is promoted by yttrium oxide additives. Therefore it was of interest to study ZrO 2 -Y 2 O 3 systems, characterized by an increased content of this metastable phase.The aim of this work was to determine the effect of the calcination temperature on the acid-base characteristics of ZrO 2 -Y 2 O 3 and to establish the connection between the acid-base characteristics and the catalytic properties of these samples in synthesis of dimethyl carbonate from methanol and carbon dioxide. EXPERIMENTALIn this work, we investigated samples of ZrO 2 stabilized by Y 2 O 3 (3.4 mole %) (YSZ series: yttrium stabilized zirconia), prepared at the A. A. Galkin Donets'k Physicotechnical Institute (National Academy of Sciences of Ukraine) by

show abstract

Effects of zirconia phase on the synthesis of higher alcohols over zirconia and modified zirconia

Cited by 80 publications

References 22 publications

A Comparative Discussion of the Catalytic Activity and CO2-Selectivity of Cu-Zr and Pd-Zr (Intermetallic) Compounds in Methanol Steam Reforming

A Comparative Discussion of the Catalytic Activity and CO2-Selectivity of Cu-Zr and Pd-Zr (Intermetallic) Compounds in Methanol Steam Reforming

Fast and Tunable Synthesis of ZrO₂ Nanocrystals: Mechanistic Insights into Precursor Dependence

Effect of acid–base characteristics of ZrO2–Y2O3 on catalytic properties in carboxylation of methanol

Contact Info

Product

Resources

About

Effects of zirconia phase on the synthesis of higher alcohols over zirconia and modified zirconia

Cited by 80 publications

References 22 publications

A Comparative Discussion of the Catalytic Activity and CO2-Selectivity of Cu-Zr and Pd-Zr (Intermetallic) Compounds in Methanol Steam Reforming

A Comparative Discussion of the Catalytic Activity and CO2-Selectivity of Cu-Zr and Pd-Zr (Intermetallic) Compounds in Methanol Steam Reforming

Fast and Tunable Synthesis of ZrO2 Nanocrystals: Mechanistic Insights into Precursor Dependence

Effect of acid–base characteristics of ZrO2–Y2O3 on catalytic properties in carboxylation of methanol

Contact Info

Product

Resources

About

Fast and Tunable Synthesis of ZrO₂ Nanocrystals: Mechanistic Insights into Precursor Dependence