Silylated hydrophobic zeolites with enhanced tolerance to hot liquid water

Zapata, Paula Andrea; Huang, Yi; González-Borja, Miguel Ángel; Resasco, Daniel E.

doi:10.1016/j.jcat.2013.05.024

Cited by 118 publications

(111 citation statements)

References 44 publications

Supporting

Mentioning

104

Contrasting

Order By: Relevance

“…Hydrothermal stability of zeolite frameworks has been well studied for aluminosilicates (112), and many of the conclusions are transferrable to Lewis acidic zeolites. It has been shown that the presence of silanol defect sites is the most significant factor contributing to crystallinity loss during hydrothermal treatments and that hydrophobic materials tend to be more stable (113)(114)(115)(116). The structural integrity of Lewis acid zeolites is commonly justified with powder X-ray diffraction (PXRD) patterns that are unchanged after reaction, showing that long-range crystal order is preserved (22,25,29,83).…”

Section: Irreversible Deactivationmentioning

confidence: 99%

Lewis Acid Zeolites for Biomass Conversion: Perspectives and Challenges on Reactivity, Synthesis, and Stability

Luo

Lewis

Román‐Leshkov

2016

Annu. Rev. Chem. Biomol. Eng.

151

136

View full text Add to dashboard Cite

Zeolites containing Sn, Zr, Hf, Nb, or Ta heteroatoms are versatile catalysts for the activation and conversion of oxygenated molecules owing to the unique Lewis acid character of their tetrahedral metal sites. Through fluoride-mediated synthesis, hydrophobic Lewis acid zeolites can behave as water-tolerant catalysts, which has resulted in a recent surge of experimental and computational studies in the field of biomass conversion. However, many open questions still surround these materials, especially relating to the nature of their active sites. This lack of fundamental understanding is exemplified by the many dissonant results that have been described in recent literature reports. In this review, we use a molecular-based approach to provide insight into the relationship between the structure of the metal center and its reactivity toward different substrates, with the ultimate goal of providing a robust framework to understand the properties that have the strongest influence on catalytic performance for the conversion of oxygenates.

show abstract

Section: Irreversible Deactivationmentioning

confidence: 99%

Lewis Acid Zeolites for Biomass Conversion: Perspectives and Challenges on Reactivity, Synthesis, and Stability

Luo

Lewis

Román‐Leshkov

2016

Annu. Rev. Chem. Biomol. Eng.

151

136

View full text Add to dashboard Cite

show abstract

“…The same authors also reported a systematic study with various alkylsilanes from C 2 to C 18 . [70] Hydrothermal stability of zeolites has been studied in great detail, as zeolites are the most widely used solid acid catalysts [71] and are often proposed for biomass conversion. [72,73] As shown by detailed characterization using 27 Al and 29 Si solid-state NMR and NH 3 -TPD, siloxane bridge hydrolysis was the main deactivation route in the presence of hot liquid water while zeolites treated under steam suffered from dealumination.…”

Section: Increasing Support Stability In Hydrothermal Conditionsmentioning

confidence: 99%

Improving Heterogeneous Catalyst Stability for Liquid-phase Biomass Conversion and Reforming

Héroguel

Rozmysłowicz

Luterbacher³

2015

Chimia

View full text Add to dashboard Cite

Biomass is a possible renewable alternative to fossil carbon sources. To day, many bio-resources can be converted to direct substitutes or suitable alternatives to fossil-based fuels and chemicals. However, catalyst deactivation under the harsh, often liquid-phase reaction conditions required for biomass treatment is a major obstacle to developing processes that can compete with the petrochemical industry. This review presents recently developed strategies to limit reversible and irreversible catalyst deactivation such as metal sintering and leaching, metal poisoning and support collapse. Methods aiming to increase catalyst lifetime include passivation of low-stability atoms by overcoating, creation of microenvironments hostile to poisons, improvement of metal stability, or reduction of deactivation by process engineering.

show abstract

“…Similarly, the stability of USY zeolite in water can be improved by grafting a high concentration of short alkyl chains [42]. As a result, alkyl groups cover all pockets and defects minimizing direct zeolite contact with the condensed phase [42].…”

Section: Organosilane-grafted Oxidesmentioning

confidence: 99%

“…As a result, alkyl groups cover all pockets and defects minimizing direct zeolite contact with the condensed phase [42]. Zapata et al demonstrated that hydrophobized HY zeolites can retain their crystallinity, surface area, microporosity, and acid site density in 200 °C liquid water while untreated HY zeolite collapses under the same conditions [42]. HY zeolites hydrophobized with longer alkyl chains stabilize water/oil emulsions and catalyze reactions of importance in biofuel upgrading [43].…”

Section: Organosilane-grafted Oxidesmentioning

confidence: 99%

Functional carbons and carbon nanohybrids for the catalytic conversion of biomass to renewable chemicals in the condensed phase

Matthiesen

Hoff

Liu

et al. 2014

Chinese Journal of Catalysis

View full text Add to dashboard Cite

The production of chemicals from lignocellulosic biomass provides opportunities to synthesize chemicals with new functionalities and grow a more sustainable chemical industry. However, new challenges emerge as research transitions from petrochemistry to biorenewable chemistry. Compared to petrochemisty, the selective conversion of biomass-derived carbohydrates requires most catalytic reactions to take place at low temperatures (< 300 °C) and in the condensed phase to prevent reactants and products from degrading. The stability of heterogeneous catalysts in liquid water above the normal boiling point represents one of the major challenges to overcome. Herein, we review some of the latest advances in the field with an emphasis on the role of carbon materials and carbon nanohybrids in addressing this challenge. ABSTRACTThe production of chemicals from lignocellulosic biomass provides opportunities to synthesize chemicals with new functionalities and grow a more sustainable chemical industry. However, new challenges emerge as research transitions from petrochemistry to biorenewable chemistry. Compared to petrochemisty, the selective conversion of biomass-derived carbohydrates requires most catalytic reactions to take place at low temperatures (< 300 °C) and in the condensed phase to prevent reactants and products from degrading. The stability of heterogeneous catalysts in liquid water above the normal boiling point represents one of the major challenges to overcome. Herein, we review some of the latest advances in the field with an emphasis on the role of carbon materials and carbon nanohybrids in addressing this challenge.

show abstract

Silylated hydrophobic zeolites with enhanced tolerance to hot liquid water

Cited by 118 publications

References 44 publications

Lewis Acid Zeolites for Biomass Conversion: Perspectives and Challenges on Reactivity, Synthesis, and Stability

Lewis Acid Zeolites for Biomass Conversion: Perspectives and Challenges on Reactivity, Synthesis, and Stability

Improving Heterogeneous Catalyst Stability for Liquid-phase Biomass Conversion and Reforming

Functional carbons and carbon nanohybrids for the catalytic conversion of biomass to renewable chemicals in the condensed phase

Contact Info

Product

Resources

About