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 ◽  
...  
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 ◽  
...  

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.


Author(s):  
Alexis T. Bell

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.


Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3902 ◽  
Author(s):  
R. Guil-López ◽  
N. Mota ◽  
J. Llorente ◽  
E. Millán ◽  
B. Pawelec ◽  
...  

Technological approaches which enable the effective utilization of CO2 for manufacturing value-added chemicals and fuels can help to solve environmental problems derived from large CO2 emissions associated with the use of fossil fuels. One of the most interesting products that can be synthesized from CO2 is methanol, since it is an industrial commodity used in several chemical products and also an efficient transportation fuel. In this review, we highlight the recent advances in the development of heterogeneous catalysts and processes for the direct hydrogenation of CO2 to methanol. The main efforts focused on the improvement of conventional Cu/ZnO based catalysts and the development of new catalytic systems targeting the specific needs for CO2 to methanol reactions (unfavourable thermodynamics, production of high amount of water and high methanol selectivity under high or full CO2 conversion). Major studies on the development of active and selective catalysts based on thermodynamics, mechanisms, nano-synthesis and catalyst design (active phase, promoters, supports, etc.) are highlighted in this review. Finally, a summary concerning future perspectives on the research and development of efficient heterogeneous catalysts for methanol synthesis from CO2 will be presented.


2020 ◽  
Author(s):  
Charlie Paris ◽  
Alejandro Karelovic ◽  
Raydel Manrique ◽  
Solène Le Bras ◽  
François Devred ◽  
...  

The preparation of copper-based heterogeneous catalysts dedicated to the hydrogenation of CO2 to methanol typically relies on multi-step procedures carried out in batch. These steps are precisely tailored to introduce the active phase (Cu) and the promoters (e.g. zinc, gallium) onto a preformed support, to maximize catalyst performance. However, each process step – often carried out in batch – can be associated with the formation of waste and with the consumption of energy, thereby negatively impacting the environmental performance of the overall catalyst preparation procedure. Here, we propose a direct and continuous production process for the synthesis of efficient catalysts for the CO2 to methanol reaction. Gallium- and zinc-promoted mesoporous Cu-SiO2 catalysts are prepared in one step by the aerosol-assisted sol-gel process. The catalysts consist of spherical microparticles and feature high specific surface area and pore volume, with interconnected pores of about 6 nm. A strong promoting effect of Ga and Zn is highlighted, boosting the selectivity for methanol at the expense of CO. Upon calcination, we show that Cu species – initially trapped in the silica matrix – undergo a migration towards the catalyst surface and a progressive sintering. After optimization, the catalysts obtained via such direct route compete with the best catalysts reported in the literature and obtained via multi-step approaches. <br>


2021 ◽  
Vol 5 (3) ◽  
pp. 38
Author(s):  
Emiliano Salucci ◽  
Vincenzo Russo ◽  
Tapio Salmi ◽  
Martino Di Serio ◽  
Riccardo Tesser

The study and the understanding of the importance of the morphological properties of heterogeneous catalysts can pave the way for important improvements in the performance of catalytic systems. Non-uniform active phase distribution catalysts are normally adopted for consecutive reactions to improve the selectivity to the desired intermediate product. Attributes on which minor attention is paid, such as the distribution and thickness of the active phase, can be decisive in the final rationale of the catalyst synthesis strategy. Starting from a previous work, where a single non-uniform active phase model for catalyst particles was developed, a key step to control the entire system is to include the bulk-phase equations and related transport phenomena. For this purpose, this work proposes a modeling approach of a biphasic reactive system in a batch reactor in the presence of three different kinds of catalytic particles (egg shell, egg white, and egg yolk) whose distinction lies in the localization of the active zone. The reactive network consists of a couple of reactions in series, which take place exclusively on the solid surface, and the intermediate component is the main product of interest. To reveal the influence related to the type of catalyst, an extensive parametric study was conducted, varying several structural coefficients to highlight the changes in the intraparticle and bulk concentration profiles of the different chemical species. The main results can be considered of wide interest for the chemical reaction engineering community, as it was demonstrated that mass and heat transfer limitations affect the catalyst performance. For the chosen system, the egg shell catalyst normally led to better catalytic performances.


Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6796
Author(s):  
Andrea Lazzarini ◽  
Roberta Colaiezzi ◽  
Francesco Gabriele ◽  
Marcello Crucianelli

Heterogeneous catalysts are progressively expanding their field of application, from high-throughput reactions for traditional industrial chemistry with production volumes reaching millions of tons per year, a sector in which they are key players, to more niche applications for the production of fine chemicals. These novel applications require a progressive utilization reduction of fossil feedstocks, in favor of renewable ones. Biomasses are the most accessible source of organic precursors, having as advantage their low cost and even distribution across the globe. Unfortunately, they are intrinsically inhomogeneous in nature and their efficient exploitation requires novel catalysts. In this process, an accurate design of the active phase performing the reaction is important; nevertheless, we are often neglecting the importance of the support in guaranteeing stable performances and improving catalytic activity. This review has the goal of gathering and highlighting the cases in which the supports (either derived or not from biomass wastes) share the worth of performing the catalysis with the active phase, for those reactions involving the synthesis of fine chemicals starting from biomasses as feedstocks.


Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 655 ◽  
Author(s):  
Jéssica Siqueira Mancilha Nogueira ◽  
João Paulo Alves Silva ◽  
Solange I. Mussatto ◽  
Livia Melo Carneiro

This study aimed to evaluate the synthesis and application of heterogeneous catalysts based on heteropolyacids for 5-hydroxymethylfurfural (HMF) production from glucose. Initially, assays were carried out in order to establish the most favorable catalyst synthesis conditions. For such purpose, calcination temperature (300 or 500 °C), type of support (Nb2O5 or Al2O3), and active phase (H3PW12O40—HPW or H3PMo12O40—HPMo) were tested and combined based on Taguchi’s L8 orthogonal array. As a result, HPW-Nb2O5 calcined at 300 °C was selected as it presented optimal HMF production performance (9.5% yield). Subsequently, the reaction conditions capable of maximizing HMF production from glucose using the selected catalyst were established. In these experiments, different temperatures (160 or 200 °C), acetone-to-water ratios (1:1 or 3:1 v/v), glucose concentrations (50 or 100 g/L), and catalyst concentrations (1 or 5% w/v) were evaluated according to a Taguchi’s L16 experimental design. The conditions that resulted in the highest HMF yield (40.8%) consisted of using 50 g/L of glucose at 160 °C, 1:1 (v/v) acetone-to-water ratio, and catalyst concentration of 5% (w/v). Recycling tests revealed that the catalyst can be used in four runs, which results in the same HMF yield (approx. 40%).


2020 ◽  
Author(s):  
Charlie Paris ◽  
Alejandro Karelovic ◽  
Raydel Manrique ◽  
Solène Le Bras ◽  
François Devred ◽  
...  

The preparation of copper-based heterogeneous catalysts dedicated to the hydrogenation of CO2 to methanol typically relies on multi-step procedures carried out in batch. These steps are precisely tailored to introduce the active phase (Cu) and the promoters (e.g. zinc, gallium) onto a preformed support, to maximize catalyst performance. However, each process step – often carried out in batch – can be associated with the formation of waste and with the consumption of energy, thereby negatively impacting the environmental performance of the overall catalyst preparation procedure. Here, we propose a direct and continuous production process for the synthesis of efficient catalysts for the CO2 to methanol reaction. Gallium- and zinc-promoted mesoporous Cu-SiO2 catalysts are prepared in one step by the aerosol-assisted sol-gel process. The catalysts consist of spherical microparticles and feature high specific surface area and pore volume, with interconnected pores of about 6 nm. A strong promoting effect of Ga and Zn is highlighted, boosting the selectivity for methanol at the expense of CO. Upon calcination, we show that Cu species – initially trapped in the silica matrix – undergo a migration towards the catalyst surface and a progressive sintering. After optimization, the catalysts obtained via such direct route compete with the best catalysts reported in the literature and obtained via multi-step approaches. <br>


Catalysts ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 840 ◽  
Author(s):  
Xiaofeng Wang ◽  
Wei Guo ◽  
Raed Abu-Reziq ◽  
Shlomo Magdassi

Three-dimensional (3D) printing has recently been introduced into the field of chemistry as an enabling tool employed to perform reactions, but so far, its use has been limited due to material and structural constraints. We have developed a new approach for fabricating 3D catalysts with high-complexity features for chemical reactions via digital light processing printing (DLP). PtO2-WO3 heterogeneous catalysts with complex shapes were directly fabricated from a clear solution, composed of photo-curable organic monomers, photoinitiators, and metallic salts. The 3D-printed catalysts were tested for the hydrogenation of alkynes and nitrobenzene, and displayed excellent reactivity in these catalytic transformations. Furthermore, to demonstrate the versatility of this approach and prove the concept of multifunctional reactors, a tungsten oxide-based tube consisting of three orderly sections containing platinum, rhodium, and palladium was 3D printed.


ACS Catalysis ◽  
2015 ◽  
Vol 5 (8) ◽  
pp. 4514-4518 ◽  
Author(s):  
S. Matera ◽  
S. Blomberg ◽  
M. J. Hoffmann ◽  
J. Zetterberg ◽  
J. Gustafson ◽  
...  

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