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Chemistry for industry

Homogeneous catalysts 

Prof. Karola Grela, PhD DSc; Anna Kajetanowicz, PhD DSc, Assoc. Prof.; Adrian Sytniczuk, PhD and the team

In modern times, the chemical industry faces the need to minimize the use of fossil fuels as a platform for chemical production and replace them with renewable resources. One methodology that offers a solution to this challenge is olefin metathesis.

In our research, we focus on utilizing vegetable oils as substrates for further transformations. Among other achievements, we have developed a series of catalysts for ethenolysis reactions, featuring specially designed CAAC (cyclic alkyl amino carbene) ligands. These catalysts, used in quantities as low as 0.5 ppm, allow the conversion of methyl oleate (one of a major products obtained from plant oils) into 9-DAME and 1-decene. After further transformations, these compounds find applications as lubricants, surfactants, monomers for plastic production, and in motor oil formulations, just to mentioned few. Importantly, due to their unique structure, our catalysts demonstrate enhanced stability in the presence of common deactivators such as oxygen, moisture, or typical impurities found in the substrate. This allows their use in FAME (fatty acid methyl esters) reactions, which are considered a viable feedstock for ethenolysis by leading players in the chemical industry.

Methyl oleate can also serve as a feedstock for the synthesis of α,ω-dienes, which are subsequently transformed into macrocyclic musk compounds. These are valuable products for the Flavors and Fragrances (F&F) industry, as they constitute a significant component of the base notes in perfumes. Unfortunately, for many years, the industrial application of olefin metathesis for their production was uneconomical due to the necessity of conducting reactions at very high dilutions. To address this Achilles’ heel, we have developed a method that enables the distillation of the desired product from the reaction mixture, allowing us to conduct reactions at concentrations up to 200 times higher than previously achievable.

Selected publications:

  1. Sytniczuk, M. Dąbrowski, Ł. Banach, M. Urban, S. Czarnocka-Śniadała, M. Milewski, A. Kajetanowicz, K. Grela, “At long last: olefin metathesis macrocyclization at high concentration” J. Am. Chem. Soc., 2018, 140, 8895, DOI: 10.1021/jacs.8b04820
  2. Sytniczuk, A. Leszczyńska, A. Kajetanowicz, K. Grela, “Preparation of musk-smelling macrocyclic lactones from biomass: looking for the optimal substrate combination” ChemSusChem, 2018, 11, 3157, DOI: https://doi.org/10.1002/cssc.201801463
  3. Kośnik, D. Lichosyt, M. Śnieżek, A. Janaszkiewicz, K. Woźniak, M. Malińska, B. Trzaskowski, A. Kajetanowicz, K. Grela, „Ruthenium olefin metathesis catalysts bearing macrocyclic n-heterocyclic carbene ligand: improved stability and activity” Angew. Chem. Int. Ed., 2022, 134, e202201472, DOI: https://doi.org/10.1002/anie.202201472
  4. Sytniczuk, M. Milewski, M. Dąbrowski, K. Grela, A. Kajetanowicz, “Schrock molybdenum alkylidene catalyst enables selective formation of macrocyclic unsaturated lactones by ring-closing metathesis at high-concentration” Green Chem., 2023, 25, 2299, DOI: https://doi.org/10.1039/D2GC02988J
  5. Sytniczuk, A. Kajetanowicz, K.Grela ““Inverted” cyclic(alkyl)(amino)carbene ligands allow olefin metathesis with ethylene at parts-per-billion catalyst loading” Chem Catal., 2023, 3, 100713, DOI: https://doi.org/10.1016/j.checat.2023.100713
Materials for the hydrogen economy

Adam Lewera, PhD DSc, Assoc. Prof. and the team

Generating hydrogen by electrolysis of water, using surplus electricity from renewable sources, is a potentially free source of hydrogen. However, this simple concept is hampered by the costs of electrolyzers, mainly due to the high price of precious metals used as anode and cathode catalysts in the water electrolysis reaction.

Due to the high prices of precious metals – platinum, palladium and iridium – these metals are most often used carbon-deposited nanoparticles. Pt/C catalyst developed by researchers from the Faculty of Chemistry allows for 50 % reduction of the amount of platinum used, without losing catalytic activity. This is possible due to the smaller size of nanoparticles obtained, as compared to competitive solutions, and to their more even distribution on the surface of the carbon support. Considering the very high prices of electrolysers, this catalyst provides significant savings, which opens up great opportunities for its commercialization.

And what can you do with hydrogen? It can be used as a fuel in a hydrogen-oxygen fuel cells. Such  cells are characterized by high efficiency and can be used as an energy source in passenger cars, buses, airplanes or electronic devices. The key element here is again the catalyst, practically identical to that in electrolyzers, and as in the case of electrolyzers, it constitutes a significant part of the value of such a cell. The material developed can therefore find application not only in the production of hydrogen, but also in its use.

Selected publications:

  1. Wnuk, A. Lewera, R. Jurczakowski, F. Powała, J. Kołodziejczyk “Method of synthesis of carbon-supported Platinum group metal or metal alloy nanoparticles”  PCT/PL 2022/000002, EP4271533
Electrochemical sources and energy storage

Prof. Andrzej Czerwiński, PhD DSc and the team

Carbon Lead Acid Battery (CLAB)

In commercially available lead acid batteries, the active mass in the form of lead (negative electrode) or lead oxide (positive electrode) is deposited on a carrier which is made in the form a lead alloy. This grid does not take part in electrode processes, significantly and unnecessarily increasing the weight of the battery. In the current solution, instead of a lead alloy grid, porous conductive glassy carbon (CPC) produced in the LEPS additionally covered with a very thin layer of lead is used in the positive and negative plate of the battery. Thanks to this solution, the electrical contact with the active mass of the battery is three-dimensional (3D), and not 2D, as was the case with previous solutions. As a result, the efficiency of the charge obtained from the active mass increases by 20 – 30%, and the electrical capacity of the battery has been increased by more than 50% compared to commercial products.   In addition, the lead content in the battery has been reduced by 40%. Due to the above solution, all parameters of the battery have been improved significantly.   Increased cyclic resistance (over 3000 cycles) guarantees the proper functioning of the battery with photovoltaic panels for over 8 years. The CLAB battery is also resistant to high discharge and charging currents (up to 9C), e.g. after 200 cycles (100% DoD) at 5C the battery loses only 20% of its initial capacity. The presented battery is characterized by low self-discharge (50% within 2 years) and stability of operation in a wide range of temperatures (-30oC – 50oC). The production cost of 1 kWh at CLAB is lower with currently existing lead batteries used in energy storage This battery can be used as a low-cost energy storage for intermittent energy sources (RES), such as wind and solar power plants.  CLAB can also be used as a starter battery in vehicles with internal combustion engines.  It should be mentioned that every electrically powered vehicle is also equipped with a lead-acid battery.   This means that the new battery can be used in electric and hybrid vehicles.

It should be noted that the above solution was used in an experimental energy storage station with a capacity of 15 kWh powered by 10 kW photovoltaic panels. These devices were installed as part of the NCBR project at the Faculty of Chemistry of the University of Warsaw (Radiochemistry).

The developed solution is a breakthrough in the over 160-year history of lead-acid batteries. The new generation of carbon acid batteries may compete with other, much more expensive cells, such as lithium ions cells. Due to the safety of use, large lead deposits in Europe (including Poland) and the already existing 100% recycling, this design may also compete with lithium cells in the current rapid development of energy storage.

Selected publications:

  1. Czerwiński, S. Obrębowski, Z. Rogulski “New high-energy lead-acid battery with reticulated vitreous carbon as a carrier and current collector”, J. Power Sources, 2012, 198, 378, DOI: https://doi.org/10.1016/j.jpowsour.2011.09.081
  2. Czerwiński, J. Wróbel, J. Lach, K. Wróbel, Piotr Podsadni, “The charging-discharging behavior of the lead-acid cell with electrodes based on carbon matrix” J. Solid State Electrochem., 2018, 22, 2703, DOI: https://doi.org/10.1007/s10008-018-3981-4
  3. Patents PL: 167796, 178258, 180939, 211599   211918 , 235916, 234791, 234791, 235550

 

New electrochemical supercapacitor

A system in the form of a thin layer of palladium or its alloy deposited on a hydrogen neutral material (e.g. Au, a carbon-conductive one) was used to construct a new electrochemical capacitor. This problem was solved due to basic work on palladium and its alloys, which has been ended ended with the development and application of so-called  limited volume electrodes (LVE) method, in which palladium and its alloys were deposited in the form of ultra-thin layers (0.1-1 μm) on a hydrogen-neutral substrate. As a result, in a short time, all the absorbed hydrogen can be quickly removed from this layer by electrooxidation and, conversely, introduced (absorbed) into deposited layer very quickly. Such a system is characterized by high power (current density) with low energy capacity (small amount of adsorbed hydrogen), which is advantageous due to the possibility of quick recharging without major „damage” to the capacity of  powering  source of energy, which can be a classic battery, e.g. a hydride-nickel cell (Ni-MH). The Pd-Ru and Pd-Rh alloys show a 20% increase in hydrogen absorption capacity compared to palladium. In order to reduce the total mass of the supercapacitor, a specially produced super conductive porous glassy carbon (SCPC) was used as a substrate, thanks to which the obtained pseudo-capacitance values are competitive in relation to other systems of this type (> 500 F/g). The thin layer of Pd-Rh itself has a pseudo-capacitance of about 2300 F/g with a specific energy of 175 J/g and a specific power of 250 W/g. The properties of the proposed supercapacitors can be regulated by their composition, e.g. the introduction of a strong catalyst into the platinum alloy (12%), reduces the specific energy capacity of the supercapacitor to 60 J/g, while increasing its power (accelerated hydrogen oxidation) to approx. 400 W/g.

The resulting electrochemical supercapacitor is ideal for hybrid battery construction, in which it is expected to increase their power, i.e. increase the obtained current density. For example, an asymmetric electrochemical capacitor (Pd/C) was introduced into a Ni-MH hydride cell (by connecting in parallel with the anode – a hydrophobic alloy AB5) operating at the same voltages as the hydride cell thanks to the same anode reaction, which is the oxidation of the absorbed hydrogen also the surface of AB5 alloy was decorated with Pd nanoparticules. The common positive electrode in this cell was NiOOH. As a result, the initial (approx. 100s) discharge currents were increased by more than 50%, i.e. the initial power of the cell increased by approx. 50%, despite the fact that the total share of palladium in the hybrid Pd+AB5 system is only approx. 0.36%. Thanks to such measures, it is possible to bring the operating parameters of the bag cell closer to the so-called high-power lithium-ion cells, which are much more expensive and less safe.

The new electrochemical system in the form of a thin layer of palladium (Pd alloys) alloy deposited on a hydrogen-neutral substrate as well as nanoparticules deposited on the surface hydrogen absorbing alloys can be used as a supercapacitor with significant powers, increasing the usable parameters of the Ni-MH battery.

Selected publications:

  1. Łukaszewski , A. Żurowski, A. Czerwiński “Hydrogen in thin Pd-based layers deposited on reticulated vitreous carbon – a new  system for electrochemical capacitors” J. Power Sources, 2008, 185, 1598, DOI: https://doi.org/10.1016/j.jpowsour.2008.08.002
  2. Łukaszewski, K. Hubkowska, U. Koss, A. Czerwiński “Characteristic of hydrogen-saturated Pd-based alloys for the application in electrochemical capacitors” J. Solid State Electrochem.,2012, 16, 2533, DOI: https://doi.org/10.1007/s10008-012-1658-y
  3. Patent PL 204948 B1, patent pending P.414861