scholarly journals High Performance Tunable Catalysts Prepared by Using 3D Printing

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5017
Author(s):  
Cristian Yesid Chaparro-Garnica ◽  
Esther Bailón-García ◽  
Arantxa Davó-Quiñonero ◽  
Patrick Da Costa ◽  
Dolores Lozano-Castelló ◽  
...  
Keyword(s):  
Heterogeneous Catalysis ◽  
3D Printing ◽  
High Performance ◽  
Heterogeneous Catalysts ◽  
Active Phase ◽  
The Novel ◽  
Co2 Methanation ◽  
New Synthesis ◽  
Carbon Dioxide Hydrogenation ◽  
Novel Design

Honeycomb monoliths are the preferred supports in many industrial heterogeneous catalysis reactions, but current extrusion synthesis only allows obtaining parallel channels. Here, we demonstrate that 3D printing opens new design possibilities that outperform conventional catalysts. High performance carbon integral monoliths have been prepared with a complex network of interconnected channels and have been tested for carbon dioxide hydrogenation to methane after loading a Ni/CeO2 active phase. CO2 methanation rate is enhanced by 25% at 300 °C because the novel design forces turbulent flow into the channels network. The methodology and monoliths developed can be applied to other heterogeneous catalysis reactions, and open new synthesis options based on 3D printing to manufacture tailored heterogeneous catalysts.

Evaluation of the Adhesion of a Novel Design of Veneers to Dental Materials

2017 ◽  
Vol 68 (9) ◽  
pp. 2125-2128
Author(s):  
Alexandra Cristina Maroiu ◽  
Cosmin Sinescu ◽  
Radu Negru ◽  
Liviu Marsavina ◽  
Ioana Delia Bretean ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
High Performance ◽  
Dental Materials ◽  
In Vitro Study ◽  
The Novel ◽  
Adhesive Properties ◽  
Computer Aided ◽  
Aided Design ◽  
Novel Design

The aim of this in vitro study was to assess a new design that, to our knowledge, we have introduced (patent pending) for indirect dental veneers. Their effect on the retention and adhesive properties at their interfaces have been studied. Fourteen high performance polymeric (PEEK) dental veneers have been elaborated using a computer-aided-design (CAD) software and then milled using a computer-aided-machine (CAM). They were divided in two experimental groups: seven classical veneers with a liniar marginal contour and seven dental veneers with the novel proposed sinusoidal marginal design. All the samples have been bonded to polymeric blocks that had the vestibular face prepared in a specific way for each group. The values of the retention and adhesive forces were tested in vitro by applying bending forces on the incisal edge of the veneers, from the oral to the vestibular direction. A 50% increase of the values of these forces for the novel design with regard to the classical one has been demonstrated through the study.

Customizable Heterogeneous Catalysts: Nonchanneled Advanced Monolithic Supports Manufactured by 3D-Printing for Improved Active Phase Coating Performance

2020 ◽  
Vol 12 (49) ◽  
pp. 54573-54584
Author(s):  
Cristian Y. Chaparro-Garnica ◽  
Pepe Jordá-Faus ◽  
Esther Bailón-García ◽  
Raúl Ocampo-Pérez ◽  
Carlos G. Aguilar-Madera ◽  
...  
Keyword(s):  
3D Printing ◽  
Heterogeneous Catalysts ◽  
Active Phase ◽  
Coating Performance ◽  
Phase Coating

scholarly journals A New 4 × 4 Rectangular Waveguide Short-Slot Coupler in 3D Printed Technology at Ku-Band

Electronics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 610
Author(s):  
Raúl V. Haro-Baez ◽  
Jorge A. Ruiz-Cruz ◽  
Juan Córcoles ◽  
José R. Montejo-Garai ◽  
Jesús M. Rebollar
Keyword(s):  
3D Printing ◽  
Rectangular Waveguide ◽  
High Performance ◽  
Low Cost ◽  
Silver Coating ◽  
Compact Structure ◽  
Coupling Region ◽  
3D Printed ◽  
Good Trade ◽  
Novel Design

This paper presents a novel design of an eight-port directional coupler with a very compact structure and simple manufacturing, working in the Ku frequency band. One of the main goals of the design was to ease the manufacturing with a simple structure: the coupler consisted of four rectangular waveguide input ports, four rectangular waveguide output ports, and a central coupling region with only H-plane variation. A prototype was fabricated using additive manufacturing, with a combination of 3D printing and silver coating metallization. The obtained performance showed a theoretical bandwidth of 6.6% with 20 dB return loss for the input/output ports. Good agreement between simulations and measurements was obtained, validating the proposed coupler as a good trade-off for low cost 3D printing, compactness, and high performance for systems requiring a high number of ports as in phase arrays or Butler matrices.

Ultrathin paper-like boron-doped carbon nanosheet electrodes combined with boron-enriched gel polymer electrolytes for high-performance energy storage

2016 ◽  
Vol 4 (40) ◽  
pp. 15589-15596 ◽  
Author(s):  
Chuanlin Cai ◽  
Ping Yuan ◽  
Jiayong Tang ◽  
Yanhui Guo ◽  
Xiaohua Ma
Keyword(s):  
Energy Storage ◽  
Polymer Electrolytes ◽  
High Performance ◽  
Electrochemical Performances ◽  
Gel Polymer Electrolytes ◽  
The Novel ◽  
Boron Doped ◽  
Doped Graphene ◽  
Graphene Paper ◽  
Novel Design

The novel design of B-doped graphene paper electrodes combined with B-enriched gel polymer electrolytes endows symmetric SCs with outstanding electrochemical performances.

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.

scholarly journals Microwaves and Heterogeneous Catalysis: A Review on Selected Catalytic Processes

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 246 ◽  
Author(s):  
Vincenzo Palma ◽  
Daniela Barba ◽  
Marta Cortese ◽  
Marco Martino ◽  
Simona Renda ◽  
...  
Keyword(s):  
Heterogeneous Catalysis ◽  
Energy Saving ◽  
Microwave Heating ◽  
Microwave Radiation ◽  
Heterogeneous Catalysts ◽  
Conventional Heating ◽  
Specific Effects ◽  
Natural Choice ◽  
Future Challenges ◽  
Catalyzed Reactions

Since the late 1980s, the scientific community has been attracted to microwave energy as an alternative method of heating, due to the advantages that this technology offers over conventional heating technologies. In fact, differently from these, the microwave heating mechanism is a volumetric process in which heat is generated within the material itself, and, consequently, it can be very rapid and selective. In this way, the microwave-susceptible material can absorb the energy embodied in the microwaves. Application of the microwave heating technique to a chemical process can lead to both a reduction in processing time as well as an increase in the production rate, which is obtained by enhancing the chemical reactions and results in energy saving. The synthesis and sintering of materials by means of microwave radiation has been used for more than 20 years, while, future challenges will be, among others, the development of processes that achieve lower greenhouse gas (e.g., CO2) emissions and discover novel energy-saving catalyzed reactions. A natural choice in such efforts would be the combination of catalysis and microwave radiation. The main aim of this review is to give an overview of microwave applications in the heterogeneous catalysis, including the preparation of catalysts, as well as explore some selected microwave assisted catalytic reactions. The review is divided into three principal topics: (i) introduction to microwave chemistry and microwave materials processing; (ii) description of the loss mechanisms and microwave-specific effects in heterogeneous catalysis; and (iii) applications of microwaves in some selected chemical processes, including the preparation of heterogeneous catalysts.

Rational Design of a High Performance and Robust Solar Evaporator via 3D‐Printing Technology

2021 ◽  
pp. 2102649
Author(s):  
Sourav Chaule ◽  
Jongha Hwang ◽  
Seong‐Ji Ha ◽  
Jihun Kang ◽  
Jong‐Chul Yoon ◽  
...  
Keyword(s):  
3D Printing ◽  
High Performance ◽  
Rational Design ◽  
Printing Technology ◽  
3D Printing Technology

scholarly journals Sample Environment for Operando Hard X-ray Tomography—An Enabling Technology for Multimodal Characterization in Heterogeneous Catalysis

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 459
Author(s):  
Johannes Becher ◽  
Sebastian Weber ◽  
Dario Ferreira Sanchez ◽  
Dmitry E. Doronkin ◽  
Jan Garrevoet ◽  
...  
Keyword(s):  
Heterogeneous Catalysis ◽  
Synchrotron Radiation ◽  
Contrast Imaging ◽  
Co2 Methanation ◽  
Full Field ◽  
X Ray ◽  
Spatially Resolved ◽  
Oxidation Of Methane ◽  
Unique Source ◽  
Sample Environment

Structure–activity relations in heterogeneous catalysis can be revealed through in situ and operando measurements of catalysts in their active state. While hard X-ray tomography is an ideal method for non-invasive, multimodal 3D structural characterization on the micron to nm scale, performing tomography under controlled gas and temperature conditions is challenging. Here, we present a flexible sample environment for operando hard X-ray tomography at synchrotron radiation sources. The setup features are discussed, with demonstrations of operando powder X-ray diffraction tomography (XRD-CT) and energy-dispersive tomographic X-ray absorption spectroscopy (ED-XAS-CT). Catalysts for CO2 methanation and partial oxidation of methane are shown as case studies. The setup can be adapted for different hard X-ray microscopy, spectroscopy, or scattering synchrotron radiation beamlines, is compatible with absorption, diffraction, fluorescence, and phase-contrast imaging, and can operate with scanning focused beam or full-field acquisition mode. We present an accessible methodology for operando hard X-ray tomography studies, which offer a unique source of 3D spatially resolved characterization data unavailable to contemporary methods.

scholarly journals High-Speed 3D Printing of High-Performance Thermosetting Polymers via Two-Stage Curing

2018 ◽  
Vol 39 (7) ◽  
pp. 1700809 ◽  
Author(s):  
Xiao Kuang ◽  
Zeang Zhao ◽  
Kaijuan Chen ◽  
Daining Fang ◽  
Guozheng Kang ◽  
...  
Keyword(s):  
3D Printing ◽  
High Speed ◽  
High Performance ◽  
Two Stage ◽  
Thermosetting Polymers
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