scholarly journals Bio-Templating: An Emerging Synthetic Technique for Catalysts. A Review

Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1364
Author(s):  
M. Carmen Herrera-Beurnio ◽  
Jesús Hidalgo-Carrillo ◽  
Francisco J. López-Tenllado ◽  
Juan Martin-Gómez ◽  
Rafael C. Estévez ◽  
...  

In the last few years, researchers have focused their attention on the synthesis of new catalyst structures based on or inspired by nature. Biotemplating involves the transfer of biological structures to inorganic materials through artificial mineralization processes. This approach offers the main advantage of allowing morphological control of the product, as a template with the desired morphology can be pre-determined, as long as it is found in nature. This way, natural evolution through millions of years can provide us with new synthetic pathways to develop some novel functional materials with advantageous properties, such as sophistication, miniaturization, hybridization, hierarchical organization, resistance, and adaptability to the required need. The field of application of these materials is very wide, covering nanomedicine, energy capture and storage, sensors, biocompatible materials, adsorbents, and catalysis. In the latter case, bio-inspired materials can be applied as catalysts requiring different types of active sites (i.e., redox, acidic, basic sites, or a combination of them) to a wide range of processes, including conventional thermal catalysis, photocatalysis, or electrocatalysis, among others. This review aims to cover current experimental studies in the field of biotemplating materials synthesis and their characterization, focusing on their application in heterogeneous catalysis.

2021 ◽  
Author(s):  
Atyeh Rahmanzadeh ◽  
Mahyar Rezvani ◽  
Masoud Darvish Ganji

Abstract Regarding the deleterious effects of corrosion for a wide range of metals and alloys, many different techniques have been developed to protect the metals against corrosion. Utilizing organic inhibitors, especially those that contain heteroatoms and multiple bonds has been found an effective approach. In this research, the adsorption of a novel green inhibitor, Laurhydrazide N′-propan-3-one (LHP), on the Zn (110) surface was investigated using dispersion corrected DFT calculations. Interaction energy and electronic structures were calculated for different orientations of the inhibitor toward the Zn surface. The validity of calculated interaction energy has been verified by the MP2 level of theory. The AIM theory analysis revealed that LHP bound strongly to the Zn surface through its O active site and also its orientation affects greatly the interaction energy. Furthermore, diffusion of LHP through its O atoms active sites was observed with the state-of-the-art DFT-MD simulation during the simulation procedure that agrees well with the experiments for similar molecules adsorbed on the metal surfaces. The presented findings afford a vital insight into the interactive nature of adsorbed inhibitors on metallic surfaces and will help to develop advanced functional materials in coating technologies.


2021 ◽  
Author(s):  
Hassan Aljama ◽  
Martin Head-Gordon ◽  
Alexis Bell

Abstract Cation exchanged-zeolites are functional materials with a wide range of applications from catalysis to sorbents. They present a challenge for computational studies using density functional theory due to the numerous possible active sites. From Al configuration, to placement of extra framework cation(s), to potentially different oxidation states of the cation, accounting for all these possibilities is not trivial. To make the number of calculations more tractable, most studies focus on a few active sites. We attempt to go beyond these limitations by implementing a workflow for a high throughput screening, designed to systematize the problem and exhaustively search for feasible active sites. We use Pd-exchanged CHA and BEA to illustrate the approach. After conducting thousands of individual calculations, we identify the sites most favorable for the Pd cation and discuss the results in detail. The high throughput screening identifies many energetically favorable sites that are non-trivial. Lastly, we employ these results to examine NO adsorption in Pd-exchanged CHA, which is a promising passive NOx adsorbent (PNA) during the cold start of automobiles. The results shed light on critical active sites for NOx capture that were not previously studied.


Author(s):  
Nikolaos Chalmpes ◽  
Georgios Asimakopoulos ◽  
Maria Baikousi ◽  
Athanasios B. Bourlinos ◽  
Michael A. Karakassides ◽  
...  

Hypergolic materials synthesis is a new preparative technique in materials science that allows a wide range of carbon or inorganic solids with useful properties to be obtained. Previously we have demonstrated that metallocenes are versatile reagents in the hypergolic synthesis of inorganic materials, such as γ-Fe2O3, Cr2O3, Co, Ni and alloy CoNi. Here, we take one step further by using metallocene dichlorides as precursors for the hypergolic synthesis of additional inorganic phases, such as photocatalytic titania. Metallocene dichlorides are closely related to metallocenes, thus expanding the arsenal of organometallic compounds that can be used in hypergolic materials synthesis. In the present case, we show that hypergolic ignition of the titanocene dichloride-fuming nitric acid pair results in the fast and spontaneous formation of titania nanoparticles at ambient conditions in the form of anatase-rutile mixed phases. The obtained titania shows good photocatalytic activity towards Cr(VI) removal (100 % within 9 h), the latter being dramatically enhanced after calcination of the powder at 500 °C (100 % within 3 h). Worth noting, this performance was found to be comparable to that of commercially available P25 TiO2 under identical conditions. The cases of zirconocene, hafnocene and molybdocene dichlorides are complementary discussed in this work, aiming to show the wider applicability of metallocene dichlorides in the hypergolic synthesis of inorganic materials (ZrO2, HfO2, MoO2).


Author(s):  
Karthik Pushpavanam ◽  
Jinrong Ma ◽  
Yifeng Cai ◽  
Nada Y. Naser ◽  
François Baneyx

There is considerable interest in the development of hybrid organic–inorganic materials because of the potential for harvesting the unique capabilities that each system has to offer. Proteins are an especially attractive organic component owing to the high amount of chemical information encoded in their amino acid sequence, their amenability to molecular and computational (re)design, and the many structures and functions they specify. Genetic installation of solid-binding peptides (SBPs) within protein frameworks affords control over the position and orientation of adhesive and morphogenetic segments, and a path toward predictive synthesis and assembly of functional materials and devices, all while harnessing the built-in properties of the host scaffold. Here, we review the current understanding of the mechanisms through which SBPs bind to technologically relevant interfaces, with an emphasis on the variables that influence the process, and highlight the last decade of progress in the use of solid-binding proteins for hybrid and hierarchical materials synthesis. Expected final online publication date for the Annual Review of Chemical and Biomolecular Engineering, Volume 12 is June 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


Author(s):  
H. Du ◽  
S. H. Ng ◽  
K. T. Neo ◽  
M. Ng ◽  
I. S. Altman ◽  
...  

The combination of organic and inorganic materials forms unique composites with properties that neither of the two components provides. Such functional materials are considered innovative advanced materials that enable applications in many fields, including optics, electronics, separation membranes, protective coatings, catalysis, sensors, biotechnology, and others. The challenge of incorporating inorganic particles into an organic matrix still remains today, especially for nanoparticles, due to the difficulties in their dispersion, de-agglomeration and surface modification. NanoGram has pioneered a nanomaterials synthesis technology based on laser pyrolysis process to produce a wide range of crystalline nanomaterials including complex metal oxides, nitrides and sulfides and with precisely controlled compositions, crystal structure, particle size and size distributions. In this paper we will present some examples of nanocomposites prepared using different polymer host materials and phase-pure rutile TiO2. The inorganic component can be dispersed at higher 50 weight percent into the polymer matrix. We have demonstrated a 0.2–0.3 increase of refractive index in the composite over that of host polymer while maintaining high optical transparency. These nanocomposites can be used in a range of applications or optical devices, such as planar waveguides, flat panel displays, optical sensors, high-brightness LEDs, diffraction gratings and optical data storage. Experimental data on TiO2 nanoparticle characterization, dispersion technique, surface modification and will be presented and nanocomposite properties discussed.


2009 ◽  
Vol 37 (4) ◽  
pp. 687-691 ◽  
Author(s):  
Carole C. Perry ◽  
Siddharth V. Patwardhan ◽  
Olivier Deschaume

Interactions between inorganic materials and biomolecules at the molecular level, although complex, are commonplace. Examples include biominerals, which are, in most cases, facilitated by and in contact with biomolecules; implantable biomaterials; and food and drug handling. The effectiveness of these functional materials is dependent on the interfacial properties, i.e. the extent of molecular level ‘association’ with biomolecules. The present article gives information on biomolecule–inorganic material interactions and illustrates our current understanding using selected examples. The examples include (i) mechanism of biointegration: the role of surface chemistry and protein adsorption, (ii) towards improved aluminium-containing materials, and (iii) understanding the bioinorganic interface: experiment and modelling. A wide range of experimental techniques (microscopic, spectroscopic, particle sizing, thermal methods and solution methods) are used by the research group to study interactions between (bio)molecules and molecular and colloidal species that are coupled with computational simulation studies to gain as much information as possible on the molecular-scale interactions. Our goal is to uncover the mechanisms underpinning any interactions and to identify ‘rules’ or ‘guiding principles’ that could be used to explain and hence predict behaviour for a wide range of (bio)molecule–mineral systems.


2020 ◽  
Author(s):  
Matthew J. McDermott ◽  
Shyam S. Dwaraknath ◽  
Kristin A. Persson

Abstract Accelerated synthesis of inorganic materials remains a significant challenge in the search for novel, functional materials. Many of the chemical principles which enable "synthesis by design" in synthetic organic chemistry do not exist in solid-state chemistry, despite extensive computed/experimental thermochemistry data. We present a chemical reaction network model constructed from thermochemistry databases that captures features of the thermodynamic phase space which synthesis reactions traverse. Directed edges in the network are assigned weights via a transformation that maps reaction parameters to costs. We devise a computationally tractable approach for suggesting likely reaction pathways via application of pathfinding algorithms and linear combination of lowest-cost paths in the network. We demonstrate initial success of the reaction network in predicting a complex metathesis reaction pathway toward yttrium manganese oxide YMnO3. The reaction network presents new opportunities for enabling reaction pathway prediction, rapid iteration between experimental/theoretical results, and ultimately, control of synthesis of solid-state materials.


Sci ◽  
2021 ◽  
Vol 3 (4) ◽  
pp. 46
Author(s):  
Nikolaos Chalmpes ◽  
Georgios Asimakopoulos ◽  
Maria Baikousi ◽  
Athanasios B. Bourlinos ◽  
Michael A. Karakassides ◽  
...  

Hypergolic materials synthesis is a new preparative technique in materials science that allows a wide range of carbon or inorganic solids with useful properties to be obtained. Previously we have demonstrated that metallocenes are versatile reagents in the hypergolic synthesis of inorganic materials, such as γ-Fe2O3, Cr2O3, Co, Ni and alloy CoNi. Here, we go one step further by using metallocene dichlorides as precursors for the hypergolic synthesis of additional inorganic phases, such as photocatalytic titania. Metallocene dichlorides are closely related to metallocenes, thus expanding the arsenal of organometallic compounds that can be used in hypergolic materials synthesis. In the present case, we show that hypergolic ignition of the titanocene dichloride–fuming nitric acid pair results in the fast and spontaneous formation of titania nanoparticles at ambient conditions in the form of anatase–rutile mixed phases. The obtained titania shows good photocatalytic activity towards Cr(VI) removal (100% within 9 h), with the latter being dramatically enhanced after calcination of the powder at 500 °C (100% within 3 h). Notably, this performance was found to be comparable to that of commercially available P25 TiO2 under identical conditions. The cases of zirconocene, hafnocene and molybdocene dichlorides are discussed in this work, which aims to show the wider applicability of metallocene dichlorides in the hypergolic synthesis of inorganic materials (ZrO2, HfO2, MoO2).


Langmuir ◽  
2018 ◽  
Vol 35 (28) ◽  
pp. 9101-9114 ◽  
Author(s):  
Yukti Arora ◽  
Charu Seth ◽  
Deepa Khushalani

2015 ◽  
Vol 1 (1) ◽  
pp. e1400035 ◽  
Author(s):  
Zhong-Li Wang ◽  
Dan Xu ◽  
Hai-Xia Zhong ◽  
Jun Wang ◽  
Fan-Lu Meng ◽  
...  

Nonprecious carbon catalysts and electrodes are vital components in energy conversion and storage systems. Despite recent progress, controllable synthesis of carbon functional materials is still a great challenge. We report a novel strategy to prepare simultaneously Fe-N-C catalysts and Fe3O4/N-doped carbon hybrids based on the sol-gel chemistry of gelatin and iron with controllability of structure and component. The catalysts demonstrate higher catalytic activity and better durability for oxygen reduction than precious Pt/C catalysts. The active sites of FeN4/C (D1) and N-FeN2+2/C (D3) are identified by Mössbauer spectroscopy, and most of the Fe ions are converted into D1 or D3 species. The oxygen reduction reaction (ORR) activity correlates well with the surface area, porosity, and the content of active Fe-Nx /C (D1 + D3) species. As an anode material for lithium storage, Fe3O4/carbon hybrids exhibit superior rate capability and excellent cycling performance. The synthetic approach and the proposed mechanism open new avenues for the development of sustainable carbon-based functional materials.


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