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A series of zirconium-based MOFs with acclaimed stability was prepared and their ability to adsorb polyfluorinated pollutants was compared. A novel fluorinated UiO-67 analogue, UiO-67-F2, was synthesised alongside three previously reported materials: UiO-67-NH2, UiO-68-(CF3)2 and UiO-67. The structures were established and confirmed by powder X-Ray diffraction. UiO-67-NH2, UiO-68(CF3)2 and UiO-67-F2 were examined as sorbents for the perfluorinated gas, sulphur hexafluoride (SF6) from the gaseous phase. The SF6 uptake of UiO-67-NH2 and UiO-67-F2 at 100 kPa, 293 K, was high (5.54 and 5.24 mmol g -1 respectively). UiO-67-F2 exhibited a remarkable perfluorinated octanoic acid (PFOA) uptake of 928 mgPFOA g -1MOF in an aqueous solution, which far exceeded that of unmodified UiO-67 (872 mgPFOA g -1MOF at 1 000 mgPFOA L -1Water PFOA). This study has identified strengths and potential applications of the novel UiO-67-F2 and the impact of fluorine functionalization. The study also offers insight into the structure-property relations of UiO-based MOFs for their use as low-pressure SF6 storage materials and PFAS sorbents intended for water purification under ambient conditions.

Anthropogenic greenhouse gas emissions pose a serious threat to our environment. Therefore, the development of efficient systems to mitigate these issues is of utmost importance. In recent years, Sulphur hexafluoride (SF ) has garnered increasing attention due to its global warming potential, which greatly exceeds that of CO2 on a 100-year scale. These studies were undertaken to investigate SF6 sorption in novel metal-organic framework materials (MOFs)and how their components affect their function. First, the influence of secondary building units on coordination and sorption properties (SBUs) of SF6 on Ytterbium, Thulium, Cerium and Hafnium 1,3,6,8-tetrakis(4-carboxyphenyl) pyrene-based (TBAPy4−) MOFs was investigated. Secondly, the possibility of altering surface-chemical properties by pre-synthesis fluorination/amination of UIO-67/68 isostructures was studied. In the first case, the SF6 sorption properties of four novel, highly porous 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene-based (TBAPy4−) MOFs containing either Ytterbium, Thulium or Cerium all in the +3-oxidation state, orHafnium (+4) was studied. Pore size effects, coordination-effects on structure, and gas sportive propertieswere investigated and found to change and in some cases improve in the case of SF6 adsorbate. In the second case, the structures remain the same throughout these different changes, maintaining the Fmmcrystallographic space group characteristic for UIO-MOFs, enabling investigation of the effect of fluorination in isolation from other possible changes. While adding one more novel material. These changes in turn cause changes in SF6 working capacity, uptake, selectivity in simulated binary mixtures and isothermal enthalpy of adsorption. The influence of specific surface area on the isosteric enthalpy of adsorption revealed differences between functionalities. There is a multi-faceted purpose in these studies. The creation of novel structures contributes to the basic science and understanding o

Recent years have seen an increasing interest in molecular electrocatalysts for the hydrogen evolution reaction (HER). Efficient hydrogen evolution would play an important role in a sustainable fuel economy, and molecular systems could serve as highly specific and tunable alternatives to traditional noble metal surface catalysts. However, molecular catalysts are currently mostly used in homogeneous setups, where quantitative evaluation of catalytic activity is non-standardized and cumbersome, in particular for multistep, multielectron processes. The molecular design community would therefore be well served by a straightforward model for prediction and comparison of the efficiency of molecular catalysts. Recent developments in this area include attempts at applying the Sabatier principle and the volcano plot concept – popular tools for comparing metal surface catalysts – to molecular catalysis. In this work, we evaluate the predictive power of these tools in the context of experimental operating conditions, by applying them to a series of tetraphenylporphyrins employed as molecular electrocatalysts of the HER. We show that the binding energy of H and the redox chemistry of the porphyrins depend solely on the electron withdrawing ability of the central metal ion, and that the thermodynamics of the catalytic cycle follow a simple linear free energy relation. We also find that the catalytic efficiency of the porphyrins is almost exclusively determined by reaction kinetics and therefore cannot be explained by thermodynamics alone. We conclude that the Sabatier principle, linear free energy relations and molecular volcano plots are insufficient tools for predicting and comparing activity of molecular catalysts, and that experimentally useful information of catalytic performance can still only be obtained through detailed knowledge of the catalytic pathway for each individual system.

The climate crisis has created a demand for molecular catalysts that can drive redox reactions for production of sustainable fuels. To this end, we present the design, synthesis and characterization of a conducting polymer backbone functionalized with free base porphyrin pendant groups. Combining intrinsic charge transport with catalytic prospect, this system offers possibilities of molecular heterogeneous electrocatalysis with straightforward energy supply and product extraction. Using cyclic voltammetry and spectroelectrochemistry, we show that the polymerized system is stable, and that the properties of the polymer and the porphyrins are independently preserved. With in-situ conductance measurements, we demonstrate that polaronic charge transport through the polymer backbone is superimposed by redox conductivity through the porphyrin pendant groups. These results suggest that our system is a reliable fundamental structure suitable for tuning towards heterogeneous catalysis of redox reactions.

The present disclosure relates to compounds of formula IVa or IVb, or salts thereof, as intermediates in the manufacture of conducting redox polymers. L is a covalent linker moiety and R is a reversible redox group. The disclosure further relates to conducting redox polymers produced from such compounds, as well as substrates coated with such conducting redox polymers, and organic batteries comprising such conducting redox polymers.

Efficient molecular electrocatalysts are a vital part of the ongoing transition towards sustainable fuel production and away from expensive traditional noble metal catalysts. Molecular catalysts can be synthesized from earth-abundant elements and have well-defined catalytic sites [1], but are associated with poor electronic connection and impractical product separation in homogeneous setups [1-2]. We have synthesized and characterized a conducting redox polymer [3–4] consisting of a conjugated EDOT-based polymer functionalized with free base porphyrins. The polymer allows for simple surface immobilization, a higher number of catalytic units than a monolayer, and continuous charge transport to and from the redox centers of the porphyrins over a large potential window. The porphyrins are aromatic macrocyclic ligands with a rich redox chemistry that can be metallated with a wide variety of metals. Through substitution and metalation, the catalytic selectivity of these redox non-innocent compounds can be tuned towards environmentally beneficial redox reactions, such as solar-powered hydrogen evolution or CO2 reduction. Through electrochemical analysis, we have established that the individual properties of the system building-blocks are preserved, that the polymer improves porphyrin reaction kinetics, that the porphyrins are efficient conduits for electron transfer, and that the porphyrin pendant units can be metallated before or after polymerization. The system should thus be regarded as a stable fundamental platform that through appropriate molecular fine-tuning can be can be used for heterogeneous catalysis of environmentally beneficial redox reactions. References [1] A. Corma, H. Garcia, Top. Catal. 48 (2008) 8. [2] W. Herrmann, C. Kohlpaintner, Angew. Chem. Int. Ed. Engl. 32 (1993) 1524. [3] M. Sterby, R. Emanuelsson, F. Mamedov, M. Strømme, M. Sjödin, Electrochim. Acta. 308 (2019) 277. [4] G. Zotti, A. Berlin, G. Pagani, G. Schiavon, S. Zecchin, Adv. Mater. 7 (199

The climate crisis has induced the development of systems for sustainable fuel production. Considerable effort is being put into industrializing e.g. hydrogen evolution through water electrolysis, and CO2 reduction. This has increased the demand for efficient redox catalysts. With green chemistry on the rise and the selectivity-tuning abilities of molecular design, molecular catalysts are economically and environmentally sound alternatives to noble metal catalysts. We have designed a system consisting of free base porphyrins incorporated into a conducting polymer network, and successfully electropolymerized it onto glassy carbon, Au and indium tin oxide glass electrode surfaces. Using cyclic voltammetry and spectroscopic techniques, we have shown that the individual properties of the porphyrins and the polymer in the resulting film are well preserved and independent. With in-situ conductance measurements, we have also demonstrated that the polymer is conductive over a large potential window, and that polaronic charge transport through the polymer is superimposed by redox hopping via the porphyrins. Thus, our system could provide efficient charge transport between catalyst and substrate at potentials relevant for water splitting, hydrogen fuel cells and CO2 reduction. Because the system is immobilized directly onto a current collector, energy supply and product separation are straightforward. Having begun attempts at post-polymerization metalation of the free base porphyrins, we believe we have created a versatile fundamental structure that from a single synthesis route and polymerization process can be tuned towards heterogeneous catalysis of multiple environmentally beneficial reactions.

Electrocatalysts play an essential role in converting electrical energy into fuel and vice versa. A wide variety of well defined molecular catalysts have been developed to catalyze key reactions like water oxidation, proton reduction, carbon dioxide reduction etc..[1] Immobilizing molecular catalyst on electrode surface combines the benefits of having a well defined catalytic center with the benefits of heterogeneous catalysts such as efficient electronic connection between the electrode and the catalytic center.[1] Having surface constrained catalytic sites and using electrochemical methods enables the investigation of catalytic reactions at various potentials and the determination of kinetic thermodynamic parameters without mass transport limitations.[1] The immobilization of molecular catalysts on an electrode surface can be achieved by incorporating them in a conducting redox polymer.[1-3] These polymers consist of a conducting polymer backbone, such as polythiophene, and covalently bound redox active pendant groups. In this poster we present the synthesis and electrochemical characterization of conducting redox polymers bearing molecular catalysts as pendant groups. Functionalized derivatives of molecular catalysts are coupled with monomeric or trimeric units of 3,4-ethylenedioxythiophene (EDOT) or 3,4-propylenedioxythiophene (ProDOT). Subsequent electro polymerization yields functionalized electrodes which are investigated by cyclic voltammetry as well as a variety of in situ methods such as UV-vis spectroscopy, and conductance measurements.[4] References [1] R. M. Bullock et al., Chem. Eur. J. 23 (2017) 7626–7641. [2] L. Wang et al. Chem., Commun. 51 (2015) 7883–7886. [3] D. Curran et al., Chem. Soc. Rev. 20 (1991) 391. [4] M. Sterby et al., Electrochimica Acta 308 (2019) 277–284.

Utilizing organic redox-active materials as electrodes is a promising strategy to enable innovative battery designs with low environmental footprint during production, which can be hard to achieve with traditional inorganic materials. Most electrode compositions, organic or inorganic, require binders for adhesion and conducting additives to enable charge transfer through the electrode, in addition to the redox-active material. Depending on the redox-active material, many types and combinations of binders and conducting additives have been considered. We designed a conducting polymer (CP), with a soluble, trimeric unit based on 3,4-ethylenedioxythiophene (E) and 3,4-propylenedioxythiophene (P) as the repeat unit, acting as a combined binder and conducting additive. While CPs as additives have been explored earlier, in the current work, the use of a trimeric precursor enables solution processing together with the organic redox-active material. To evaluate this concept, the CP was blended with a redox polymer (RP), which contained a naphthoquinone (NQ) redox group at different ratios. The highest capacity for the total weight of the CP/RP electrode was 77 mAh/g at 1 C in the case of 30% EPE and 70% naphthoquinone-substituted poly(allylamine) (PNQ), which is 70% of the theoretical capacity given by the RP in the electrode. We further used this electrode in an aqueous battery, with a MnSO4 cathode. The battery displayed a voltage of 0.95 V, retaining 93% of the initial capacity even after 500 cycles at 1 C. The strategy of using a solution-processable CP precursor opens up for new organic battery designs and facile evaluation of RPs in such.

Rechargeable batteries that use redox-active organic compounds are currently considered an energy storage technology for the future. Functionalizing redox-active groups onto conducting polymers to make conducting redox polymers (CRPs) can effectively solve the low conductivity and dissolution problems of redox-active compounds. Here, we employ a solution-processable postdeposition polymerization (PDP) method, where the rearrangements ensured by partial dissolution of intermediated trimer during polymerization were found significant to produce high-performance CRPs. We show that quinizarin (Qz)- and naphthoquinone (NQ)-based CRPs can reach their theoretical capacity through optimization of the polymerization conditions. Combining the two CRPs, with the Qz-CRP as a cathode, the NQ-CRP as an anode, and a protic ionic liquid electrolyte, yields a 0.8 V proton rocking-chair battery. The conducting additive-free all-organic proton battery exhibits a capacity of 62 mAh/g and a capacity retention of 80% after 500 cycles using rapid potentiostatic charging and galvanostatic discharge at 4.5 C.