Nordic Consortium for CO2 Conversion

Nordic Consortium for CO2 Conversion

One more year!

The NordCO2 consortium has been extended for one year until the 31th of December 2024, giving us the opportunity to continue to support research collaborations via researcher mobility in the Nordic countries. If you are researching at one of our participating institutions, we strongly encourage you to check everyone’s specialities in order to plan the research stay that will help you advance in your project (see here). You can then start planning your trip by writing to us at nordco2@uit.no.

We will also use this opportunity to meet once last time this spring, more details will be available very soon!

Research Article: UoI

graphical abstract

Title:
Mechanistic Insights in the Catalytic Hydrogenation of CO2 over Pt Nanoparticles in UiO-67 Metal–Organic Frameworks

Abstract:
Metal nanoparticles (NPs) encapsulated within Zr-based UiO-67 metal–organic frameworks (MOFs) have increased selectivity toward methanol in CO2 reduction reactions. However, the reduction mechanism in these systems remains unclear. We built upon prior work examining the synergistic interaction between Pt nanoparticles and Zr6O4(OH)4 clusters in UiO-67 and developed five distinct models representing the possible active sites in the Pt ⊂ MOF system. Density functional theory (DFT) calculations were employed to elucidate the CO2 reduction mechanism toward methanol, methane, and CO formation. Our findings support previous evidence showing that the interface between the Zr6O4(OH)4 cluster and platinum nanoparticles plays a crucial role in the activation of CO2 to CO or formate intermediates and its further reduction to methane and methanol, respectively. Furthermore, we found different CO2 hydrogenation mechanisms for interfaces involving Pt-flat terraces and Pt-edges. On Pt terraces and interfaces near Pt terraces, the reaction goes via CO, which can be desorbed as CO(g) or be further reduced to methane. On interfaces near Pt-edges, the reaction proceeds via formate and preferably forms methanol over methane. We designed experiments to validate our computational insights involving large and small Pt nanoparticles interacting with Zr6O4(OH)4 clusters. These experiments showed that only CO and methanol were formed when smaller nanoparticles were present. Notably, methane formed with CO and methanol in the presence of larger nanoparticles, highlighting the need for flat platinum surfaces at the interfaces for methane formation. We could also associate the IR signals corresponding to CO and bidentate formate with platinum nanoparticles and Zr6O4(OH)4 clusters, respectively. Theoretical models and experimental data provided us with insights into the complexity of the reaction mechanism and emphasized the significance of understanding both the individual components of the catalytic system and their interactions in enhancing catalytic activity.

Find a list of publications by NordCO2 members on our Publications page 🙂

Research Article: UiO and AU

Title:
Solvent–base mismatch enables the deconstruction of epoxy polymers and bisphenol A recovery

Abstract:
Fiber-reinforced epoxy composites are key materials for the construction of wind turbine blades and airplanes due to their remarkable mechanical strength properties. On the flipside, their physical and chemical inertness results in a lack of viable recycling technologies. Recently, tailored resins have been introduced, which allow controlled fragmentation of the polymer matrix and thus the recovery of embedded fibres. However, for the separated thermoset epoxy fragments, there is no recycling solution available, resulting in the loss of complex molecular structures during their disposal. Here, we report a chemical process for recovering bisphenol A (BPA) from epoxy resins using a mismatched base–solvent system at an elevated temperature. We demonstrate a combinatory disassembly process/chemical deconstruction strategy on a commercial tailored composite sample, isolating both fibres and the polymer building block. The recovered BPA could potentially be reused in established polymer production chains, thus closing the recycling loop and reducing the need for virgin resources.

Find a list of publications by NordCO2 members on our Publications page 🙂

Research Article: UiT

graphical abstract

Title:
Understanding the Influence of Lewis Acids on CO2 Hydrogenation: The Critical Effect Is on Formate Rotation

Abstract:
Lewis acids (LAs) have been shown to accelerate hydrogenation of CO2, but the underlying mechanistic details remain to be elucidated. We have employed computational methods to investigate how LAs affect CO2 hydrogenation with a range of known metal-hydrides (LnIr–H, LnRu–H, LnMn–H, LnCo–H). Our results show that LAs can alter the nature of the hydride–CO2 bond formation step, but do not lower its barrier. Instead, the accelerating effect of LAs is on the subsequent step, the rearrangement of the metal-formate σ-intermediate. These insights are essential for understanding the effect of LA additives on metal-mediated hydrogenations of CO2.

Find a list of publications by NordCO2 members on our Publications page 🙂

Research Article: UiO

graphical abstract

Title:
Tracking Lattice Distortion Induced by Defects and Framework Tin in Beta Zeotypes

Abstract:
The use of powder X-ray diffraction (PXRD) coupled with lattice parameter refinement is used to investigate the crystal structure of Sn-Beta materials. A newly developed semiempirical PXRD model with a reduced tetragonal unit cell is applied to obtain the characteristic crystallographic features. There is a robust correlation between lattice parameters and the concentration of tin and defects for materials prepared via hydrothermal (HT) and postsynthetic (PT) methods. With tin incorporation, PT Sn-Beta samples, which possess a more defective structure, exhibit an extended interlayer distance in the stacking sequence and expansion of the translation symmetry within the layers, leading to larger unit cell dimensions. In contrast, HT Sn-Beta samples, having fewer defects, show a minimal effect of tin site density on the unit cell volume, whereas lattice distortion is directly correlated to the framework tin density. Furthermore, density functional theory (DFT) studies support an identical trend of lattice distortion following the monoisomorphous substitution of T sites from silicon to tin. These findings highlight that PXRD can serve as a rapid and straightforward characterization method to evaluate both framework defects and heteroatom density, offering a novel approach to monitor structural changes and the possibility to evaluate the catalytic properties of heteroatom-incorporated zeotypes.

Find a list of publications by NordCO2 members on our Publications page 🙂