Catalysis and society
Catalysis finds itself at the heart of solutions to many of society’s climate, energy, environmental and materials challenges. Heterogeneous catalysts in particular are widely adopted in today’s chemical industries, contributing in over 90 % of all industrial processes to make them more efficient, cleaner and sustainable. Developing the mainstream heterogeneous catalysts of tomorrow requires a fundamental understanding of today’s state-of-the-art catalysts.
Why are nanoparticles important in heterogeneous catalysis?
Today’s catalysts are generally composed of metallic nanoparticles (e.g. Pt, Ru, Ni, Co) deposited on an oxide support (e.g. Al2O3, TiO2, SiO2). For any catalytic reaction, the metal nanoparticle’s size and shape are known to have a profound impact on the catalytic performance of the overall catalyst.
To unravel the specific features of a metallic nanoparticle that direct its catalytic performance, extensive (in situ/operando) characterization methods are employed. These methods, which include modern electron microscopy (e.g. in situ HR-TEM, HAADF-STEM, STEM-EDX, STEM-EELS) and spectroscopy (e.g. in situ FTIR, XAS, etc.) techniques, require versatile and reproducible synthesis procedures to obtain model nanoparticles for catalytic studies.
For such fundamental studies, conventional heterogeneous catalyst synthesis methods (e.g. impregnation, coprecipitation, etc.) are often not suitable to prepare model catalysts required for advanced microscopy or spectroscopy measurements. More advanced approaches such as colloidal nanoparticle synthesis routes have cumbersome and time-consuming synthesis procedures, and require stabilizing ligands which can drastically alter or inhibit the nanoparticle’s catalytic properties. Versatile methods to produce model unsupported and supported catalysts are therefore vital to improve our understanding of catalytic systems and develop future catalysts.
VSPARTICLE & Heterogeneous Catalysis
Advantages of VSPARTICLE’s nanoparticle synthesis method
VSPARTICLE’s spark ablation technology offers a versatile method to rapidly produce nanoparticles for today’s catalysis researchers. The VSP-G1 Nanoparticle Generator (VSP-G1) is able to produce tunable metallic nanoparticles at the push of a button. These surfactant-free nanoparticles can be deposited directly onto a TEM grid or 2D substrate using the VSP-A1 Diffusion Accessory (VSP-A1). This approach was directly implemented to prepare unsupported Au nanoparticles (AuNPs) on a TEM grid. These highly crystalline AuNPs are free of stabilizing ligands/surfactants that can influence the nanoparticle shape, making these nanoparticles ideal for in situ TEM studies. In addition, by equipping the VSP-G1 with pre-alloyed electrodes, bimetallic/multi-metallic nanoparticles can be produced and studied to unravel their unique catalytic properties.
Clean nanoparticles ready for advanced catalyst characterization
Recent advances in many spectroscopic techniques have ensured that today’s highest impact catalysis researchers have embraced in situ/operando spectroscopy in their works. For example, vibrational techniques such as Raman spectroscopy can provide insights into both the surface and gas-phase species that are participating in the catalytic reaction. Advanced techniques such as Shell-Isolated Nanoparticle-Enhanced Raman Spectroscopy (SHINERS) use carefully prepared model catalysts that follow stringent preparation protocols to ensure their applicability. These strict protocols have limited the application of this technique to a handful of precious metal-based model catalysts. To improve our understanding of industrially relevant catalysts, methods to produce SHINERS active catalysts with industrially relevant metals (e.g. Ni, Co, Cu, Fe) are therefore highly desired.
Industrially relevant nickel catalysts made easy with VSPARTICLE
With the use of VSPARTICLE’s technology it has recently been demonstrated how clean Ni nanoparticles were deposited on Au@SiO2 Shell-Isolated Nanoparticles (SHINS) via spark ablation. Compared with more conventional synthesis approaches such as impregnation and colloidal Ni nanoparticle deposition, spark ablation provided SHINERS-active catalysts. Importantly, these conventional wet synthesis methods required harsh thermal conditions to remove contaminants and activate the Ni-based catalyst. Ultimately such conditions destroyed the SHINS, and were avoided by preparing Ni/Au@SiO2 via spark ablation. The spark ablation-prepared Ni/Au@SiO2 catalysts were employed for in situ Raman spectroscopy studies of industrially relevant hydrogenation reactions. The work by Wondergem et al. showcased how low transition metal catalysts can now by studied using SHINERS – a technique that was initially limited to precious metal-based catalysts.
Read More
In the last decade, the development of Electron Microscopy (EM) analysis tools has advanced significantly, with the addition of in-situ characterization capabilities. Especially for catalysis, material science and electronics research, this offers new insights into “black box” processes on the nanoscale. The EM analysis enables researchers to study material behaviour in real-time, under real-world conditions. Institutes all over the world are experimenting with the newest in-situ systems for Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDXS) and Electron Energy Loss Spectroscopy (EELS).
In the last decade, the development of Electron Microscopy (EM) analysis tools has advanced significantly, with the addition of in-situ characterization capabilities. Especially for catalysis, material science and electronics research, this offers new insights into “black box” processes on the nanoscale. The EM analysis enables researchers to study material behaviour in real-time, under real-world conditions. Institutes all over the world are experimenting with the newest in-situ systems for Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDXS) and Electron Energy Loss Spectroscopy (EELS).
VSPARTICLE is on a mission to speed up research in new nanomaterials by automating the production of advanced nanomaterials. The company introduced the VSP-G1 with the philosophy that making nanomaterials for research should be quick and easy. With the option for a four-month trial period the technology will be accessible for any researcher.