Cu-Induced [H6W12O42]6− polyoxometalate-based bimetallic cluster formation for renewable biomass inulin hydrolysis toward fructose production

2017 ◽  
Vol 4 (11) ◽  
pp. 1917-1922 ◽  
Author(s):  
Yongdong Chen ◽  
Chaolei Zhang ◽  
Jiangwei Zhang ◽  
Zhongbin Ye ◽  
Kai Zheng ◽  
...  
Keyword(s):  
Heterogeneous Catalysts ◽  
Cluster Formation ◽  
Bimetallic Cluster ◽  
Inulin Hydrolysis ◽  
Renewable Biomass

Cu3[H6W12O42] cluster heterogeneous catalysts for inulin hydrolysis towards fructose production with 100% conversion and 90% selectivity under aqueous condition are achieved.

scholarly journals A sustainable process for biodiesel production using Zn/Mg oxidic species as active, selective and reusable heterogeneous catalysts

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Marisa B. Navas ◽  
José F. Ruggera ◽  
Ileana D. Lick ◽  
Mónica L. Casella
Keyword(s):  
Castor Oil ◽  
Heterogeneous Catalysts ◽  
Catalytic Performance ◽  
High Specific Surface Area ◽  
Raw Material ◽  
Biodiesel Production ◽  
X Ray ◽  
Renewable Biomass ◽  
Butyl Esters ◽  
Mesoporous Solids

AbstractThis paper describes the preparation and characterization of MgO and ZnO-based catalysts, pure and mixed in different proportions, supported on γ-Al2O3. Their catalytic performance was studied in the transesterification of soybean oil and castor oil with methanol and butanol, attempting to produce biodiesel. XRD (X-ray diffraction), SEM–EDS (scanning electron microscopy–energy dispersive X-ray spectroscopy), CO2-adsorption and N2-adsorption allowed characterizing the prepared catalysts. The characterization results were in all cases consistent with mesoporous solids with high specific surface area. All the catalysts exhibited good results, especially in the transesterification of castor oil using butanol. For this reaction, the reuse was tested, maintaining high FABE (fatty acid butyl esters) yields after four cycles. This good performance can be attributed to the basic properties of the Mg species, and simultaneously, to the amphoteric properties of ZnO, which allow both triglycerides and free fatty acids to be converted into esters. Using these catalysts, it is possible to obtain second-generation biodiesel, employing castor oil, a raw material that does not compete with the food industry. In addition, butanol can be produced from renewable biomass.

Spectroscopic Elucidation of First Steps of Supported Bimetallic Cluster Formation

2009 ◽  
Vol 121 (51) ◽  
pp. 9877-9880 ◽  
Author(s):  
Apoorva Kulkarni ◽  
Bruce C. Gates
Keyword(s):  
Cluster Formation ◽  
Bimetallic Cluster

scholarly journals Functionalised heterogeneous catalysts for sustainable biomass valorisation

2018 ◽  
Vol 47 (22) ◽  
pp. 8349-8402 ◽  
Author(s):  
Putla Sudarsanam ◽  
Ruyi Zhong ◽  
Sander Van den Bosch ◽  
Simona M. Coman ◽  
Vasile I. Parvulescu ◽  
...  
Keyword(s):  
Energy Density ◽  
Heterogeneous Catalysts ◽  
Value Added ◽  
High Energy ◽  
High Energy Density ◽  
Renewable Biomass ◽  
Biomass Valorisation

Functionalised heterogeneous catalysts show great potentials for efficient valorisation of renewable biomass to value-added chemicals and high-energy density fuels.

scholarly journals Catalytic Thermochemical Conversion of Algae and Upgrading of Algal Oil for the Production of High-Grade Liquid Fuel: A Review

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 145 ◽  
Author(s):  
Yingdong Zhou ◽  
Changwei Hu
Keyword(s):  
Liquid Fuel ◽  
Heterogeneous Catalysts ◽  
Catalytic Conversion ◽  
Liquid Fuels ◽  
Thermochemical Conversion ◽  
Fuel Quality ◽  
High Grade ◽  
Catalytic Systems ◽  
Renewable Biomass ◽  
Algae Oil

The depletion of fossil fuel has drawn growing attention towards the utilization of renewable biomass for sustainable energy production. Technologies for the production of algae derived biofuel has attracted wide attention in recent years. Direct thermochemical conversion of algae obtained biocrude oil with poor fuel quality due to the complex composition of algae. Thus, catalysts are required in such process to remove the heteroatoms such as oxygen, nitrogen, and sulfur. This article reviews the recent advances in catalytic systems for the direct catalytic conversion of algae, as well as catalytic upgrading of algae-derived oil or biocrude into liquid fuels with high quality. Heterogeneous catalysts with high activity in deoxygenation and denitrogenation are preferable for the conversion of algae oil to high-grade liquid fuel. The paper summarized the influence of reaction parameters and reaction routes for the catalytic conversion process of algae from critical literature. The development of new catalysts, conversion conditions, and efficiency indicators (yields and selectivity) from different literature are presented and compared. The future prospect and challenges in general utilization of algae are also proposed.

What catalysis needs from the electron microscopist

1988 ◽  
Vol 46 ◽  
pp. 694-695
Author(s):  
Alexis T. Bell
Keyword(s):  
Active Sites ◽  
Heterogeneous Catalysts ◽  
Catalyst Deactivation ◽  
Surface Composition ◽  
Internal Surface ◽  
Active Phase ◽  
Atomic Scale ◽  
Metal Catalyst ◽  
Internal Surface Area ◽  
Porous Support

Heterogeneous catalysts, used in industry for the production of fuels and chemicals, are microporous solids characterized by a high internal surface area. The catalyticly active sites may occur at the surface of the bulk solid or of small crystallites deposited on a porous support. An example of the former case would be a zeolite, and of the latter, a supported metal catalyst. Since the activity and selectivity of a catalyst are known to be a function of surface composition and structure, it is highly desirable to characterize catalyst surfaces with atomic scale resolution. Where the active phase is dispersed on a support, it is also important to know the dispersion of the deposited phase, as well as its structural and compositional uniformity, the latter characteristics being particularly important in the case of multicomponent catalysts. Knowledge of the pore size and shape is also important, since these can influence the transport of reactants and products through a catalyst and the dynamics of catalyst deactivation.

Electron holography of catalysts

1995 ◽  
Vol 53 ◽  
pp. 416-417
Author(s):  
A. K. Datye ◽  
D. S. Kalakkad ◽  
L. F. Allard ◽  
E. Völkl
Keyword(s):  
Heterogeneous Catalysts ◽  
High Surface ◽  
High Surface Area ◽  
Atomic Scale ◽  
Nano Particles ◽  
Phase Image ◽  
Electron Holography ◽  
Specimen Thickness ◽  
Phase Information ◽  
Particle Structure

The active phase in heterogeneous catalysts consists of nanometer-sized metal or oxide particles dispersed within the tortuous pore structure of a high surface area matrix. Such catalysts are extensively used for controlling emissions from automobile exhausts or in industrial processes such as the refining of crude oil to produce gasoline. The morphology of these nano-particles is of great interest to catalytic chemists since it affects the activity and selectivity for a class of reactions known as structure-sensitive reactions. In this paper, we describe some of the challenges in the study of heterogeneous catalysts, and provide examples of how electron holography can help in extracting details of particle structure and morphology on an atomic scale.Conventional high-resolution TEM imaging methods permit the image intensity to be recorded, but the phase information in the complex image wave is lost. However, it is the phase information which is sensitive at the atomic scale to changes in specimen thickness and composition, and thus analysis of the phase image can yield important information on morphological details at the nanometer level.

Quantitative nano-characterization of heterogeneous catalysts

1995 ◽  
Vol 53 ◽  
pp. 398-399
Author(s):  
P.A. Crozier ◽  
M. Pan
Keyword(s):  
Heterogeneous Catalysts ◽  
Low Dose ◽  
Imaging Techniques ◽  
Structural Features ◽  
Catalyst Characterization ◽  
New Developments ◽  
Double Phase ◽  
Phase Systems ◽  
Dose Imaging

Heterogeneous catalysts can be of varying complexity ranging from single or double phase systems to complicated mixtures of metals and oxides with additives to help promote chemical reactions, extend the life of the catalysts, prevent poisoning etc. Although catalysis occurs on the surface of most systems, detailed descriptions of the microstructure and chemistry of catalysts can be helpful for developing an understanding of the mechanism by which a catalyst facilitates a reaction. Recent years have seen continued development and improvement of various TEM, STEM and AEM techniques for yielding information on the structure and chemistry of catalysts on the nanometer scale. Here we review some quantitative approaches to catalyst characterization that have resulted from new developments in instrumentation.HREM has been used to examine structural features of catalysts often by employing profile imaging techniques to study atomic details on the surface. Digital recording techniques employing slow-scan CCD cameras have facilitated the use of low-dose imaging in zeolite structure analysis and electron crystallography. Fig. la shows a low-dose image from SSZ-33 zeolite revealing the presence of a stacking fault.

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