A 3D Printer in the Lab: Not Only a Toy

Although 3D printers are becoming more common in households, they are still under-represented in many laboratories worldwide and regarded as toys rather than as laboratory equipment. This short review wants to change this conservative point of view. This mini-review focuses on fused deposition modeling printers and what happens after acquiring your first 3D printer. In short, these printers melt plastic filament and deposit it layer by layer to create the final object. They are getting cheaper and easier to use, and nowadays it is not difficult to find good 3D printers for less than €500. At such a price, a 3D printer is one, if not the most, versatile piece of equipment you can have in a laboratory.

Enhancement of wastewater treatment performance using 3D printed structures: A major focus on material composition, performance, challenges, and sustainable assessment

In order to enhance the performance and sustainability of wastewater treatment technologies, researchers are showing keen interest in the development of novel materials which can overcome the drawbacks associated with conventional materials. In this context, 3D printing gained significant attention due to its capability of fabricating complex geometrics using different material compositions. The present review focuses on recent advancements of 3D printing applications in various physicochemical and biological wastewater treatment techniques. In physicochemical treatment methods, substantial research has been aimed at fabricating feed spacers and other membrane parts, photocatalytic feed spacers, catalysts, scaffolds, monoliths, and capsules. Several advantages, such as membrane fouling mitigation, enhanced degradation efficiency, and recovery and reusability potential, have been associated with the aforementioned 3D printed materials. While in biofilm-based biological treatment methods, the use of 3D printed bio-carriers has led to enhanced mass transfer efficiency and microbial activities. Moreover, the application of these bio-carriers has shown better removal efficiency of chemical oxygen demand (∼90%), total nitrogen (∼73%), ammonia nitrogen (95%), and total phosphorous (∼100%). Although the removal efficiencies were comparable with conventional carriers, 3D printed carriers led to ∼40% reduction in hydraulic retention time, which could significantly save capital and operational expenditures. This review also emphasizes the challenges and sustainability aspects of 3D printing technology and outlines future recommendations which could be vital for further research in this field.

Review on Additive Manufacturing of Catalysts and Sorbents and the Potential for Process Intensification

Additive manufacturing of catalyst and sorbent materials promises to unlock large design freedom in the structuring of these materials, and could be used to locally tune porosity, shape and resulting parameters throughout the reactor along both the axial and transverse coordinates. This contrasts catalyst structuring by conventional methods, which yields either very dense randomly packed beds or very open cellular structures. Different 3D-printing processes for catalytic and sorbent materials exist, and the selection of an appropriate process, taking into account compatible materials, porosity and resolution, may indeed enable unbounded options for geometries. In this review, recent efforts in the field of 3D-printing of catalyst and sorbent materials are discussed. It will be argued that these efforts, whilst promising, do not yet exploit the full potential of the technology, since most studies considered small structures that are very similar to structures that can be produced through conventional methods. In addition, these studies are mostly motivated by chemical and material considerations within the printing process, without explicitly striving for process intensification. To enable value-added application of 3D-printing in the chemical process industries, three crucial requirements for increased process intensification potential will be set out: i) the production of mechanically stable structures without binders; ii) the introduction of local variations throughout the structure; and iii) the use of multiple materials within one printed structure.

3D printed tetrakis(triphenylphosphine)palladium (0) impregnated stirrer devices for Suzuki–Miyaura cross-coupling reactions

In a novel approach, SLA 3D-printed Pd(PPh3)4 containing stirrer beads have been used to catalyse the Suzuki–Miyaura reaction between a range of substrates.

Recent Advances in 3D Printing of Structured Materials for Adsorption and Catalysis Applications

Porous solids in the form of adsorbents and catalysts play a crucial role in various industrially important chemical, energy, and environmental processes. Formulating them into structured configurations is a key step toward their scale up and successful implementation at the industrial level. Additive manufacturing, also known as 3D printing, has emerged as an invaluable platform for shape engineering porous solids and fabricating scalable configurations for use in a wide variety of separation and reaction applications. However, formulating porous materials into self-standing configurations can dramatically affect their performance and consequently the efficiency of the process wherein they operate. Toward this end, various research groups around the world have investigated the formulation of porous adsorbents and catalysts into structured scaffolds with complex geometries that not only exhibit comparable or improved performance to that of their powder parents but also address the pressure drop and attrition issues of traditional configurations. In this comprehensive review, we summarize the recent advances and current challenges in the field of adsorption and catalysis to better guide the future directions in shape engineering solid materials with a better control on composition, structure, and properties of 3D-printed adsorbents and catalysts.

Controlling the structure and photocatalytic properties of three—dimensional aerogels obtained by simultaneous reduction and self-assembly of BiOI/GO aqueous colloidal dispersions

Water pollution affects all living habitats, since it is the most basic element that sustains all life forms and, as an exceptional solvent, it readily makes any compound available for living cells, either nutrients or noxious substances. Elimination of molecular contaminants from water quality is one of the most challenging technical problems that conventional treatments like flocculation and filtration fail short to defeat. Particulate photocatalysts, used to degrade contaminants, have the main drawback of their recovery from the water matrices. The inclusion of photocatalytic nanoparticles (NPs) into a large supporting framework, is presented as an innovative approach aiming to ensure a facile separation from water. To this end, three-dimensional (3D) aerogels with photocatalytic properties were prepared by a simple and scalable method based on the reduction—induced self-assembly of graphene oxide (GO) in the presence of BiOI nanoparticles. With the help of ascorbic acid, as a green reducing agent, partial reduction of GO into reduced graphene oxide (RGO) and self-assembly of both kinds of nanostructures into a porous monolith was achieved. BiOI doped RGO aerogels were further stabilized and morphologically controlled using poly (ethylene glycol) as stabilizer. The photocatalytic performance of these aerogels was evaluated by following the discoloration of methylene blue (MB) solution, under visible light irradiation, showing that structure and dispersion degree of NPs to be fundamental variables. Hence, this methodology is proposed to produce hybrid aerogels with controlled morphology and photocatalytic performance that has the potential to be used in water cleaning procedures.

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

Three-dimensional (3D)-printed catalysts are being increasingly studied; however, most of these studies focus on the obtention of catalytically active monoliths, and thus traditional channeled monolithic catalysts are usually obtained and tested, losing sight of the advantages that 3D-printing could entail. This work goes one step further, and an advanced monolith with specifically designed geometry has been obtained, taking advantage of the versatility provided by 3D-printing. As a proof of concept, nonchanneled advanced monolithic (NCM) support, composed of several transversal discs containing deposits for active phase deposition and slits through which the gas circulates, was obtained and tested in the CO-PrOx reaction. The results evidenced that the NCM support showed superior catalytic performance compared to conventional channeled monoliths (CMs). The region of temperature in which the active phase can work under chemical control, and thus in a more efficient way, is increased by 31% in NCM compared to the powdered or the CM sample. Turbulence occurs inside the fluid path through the NCM, which enhances the mass transfer of reagents and products toward and from the active sites to the fluid bulk favoring the chemical reaction rate. The nonchanneled monolith also improved heat dispersion by the tortuous paths, reducing the local temperature at the active site. Thus, the way in which reactants and products are transported inside the monoliths plays a crucial role, and this is affected by the inner geometry of the monoliths.

Metal 3D printing technology for functional integration of catalytic system

Mechanical properties and geometries of printed products have been extensively studied in metal 3D printing. However, chemical properties and catalytic functions, introduced by metal 3D printing itself, are rarely mentioned. Here we show that metal 3D printing products themselves can simultaneously serve as chemical reactors and catalysts (denoted as self-catalytic reactor or SCR) for direct conversion of C1 molecules (including CO, CO₂ and CH₄) into high value-added chemicals. The Fe-SCR and Co-SCR successfully catalyze synthesis of liquid fuel from Fischer-Tropsch synthesis and CO₂ hydrogenation; the Ni-SCR efficiently produces syngas (CO/H₂) by CO₂ reforming of CH₄. Further, the Co-SCR geometrical studies indicate that metal 3D printing itself can establish multiple control functions to tune the catalytic product distribution. The present work provides a simple and low-cost manufacturing method to realize functional integration of catalyst and reactor, and will facilitate the developments of chemical synthesis and 3D printing technology.

Metal 3D printing is a very promising technology to revolutionize catalytic systems. Here the authors show that metal 3D printing products themselves can simultaneously serve as chemical reactors and catalysts for conversion of C1 molecules into high value-added chemicals.