http://hdl.handle.net/10563/1000003 2026-07-30T13:28:45Z 2026-07-30T13:28:45Z Škoda, David Pokorný, Tomáš Hanulíková, Barbora Stýskalík, Aleš Hlavenková, Zuzana Šimoníková, Lucie Varaďa, Jan Leonová, Lucie Kuřitka, Ivo Poleunis, Claude Debecker, Damien P. http://hdl.handle.net/10563/1012852 2026-07-24T14:23:17Z 2026-01-01T00:00:00Z

Microwave-assisted one-pot sol–gel synthesis of tungsten silicate microspheres with dispersed WOx and their activity in ethanol dehydration Škoda, David; Pokorný, Tomáš; Hanulíková, Barbora; Stýskalík, Aleš; Hlavenková, Zuzana; Šimoníková, Lucie; Varaďa, Jan; Leonová, Lucie; Kuřitka, Ivo; Poleunis, Claude; Debecker, Damien P. This study introduces a novel microspherical W–SiO2 heterogeneous catalyst for alcohol dehydration, prepared via an innovative microwave-assisted condensation synthesis method. The process involves the microwave-assisted preparation of a hybrid tungsten naphthalene dicarboxylate-based precursor solution, which is subsequently condensed with (3-aminopropyl)triethoxysilane in a single step—eliminating the need for separate silica support preparation, as required in conventional impregnation methods. After calcination at 550 °C, the resulting amorphous and porous microspheres contain highly dispersed tungsten species (with loadings of 2, 6, and 12 wt%), with no crystalline WO3 phase detected, even at the highest loading. Compared to a 12 wt% WO3/SiO2 catalyst prepared via conventional impregnation, the W–SiO2 microspheres exhibit higher catalytic activity and ethylene selectivity in ethanol dehydration at 420 °C. Notably, the 2W–SiO2 catalyst achieved the highest initial ethylene productivity per mole of tungsten (520 mmol mmolW−1 h−1), maintaining 230 mmol mmolW−1 h−1 after 1000 minutes on stream, indicating high long-term stability. In terms of mass-specific performance, the 12W–SiO2 catalyst reached 133 mmol g−1 h−1, outperforming other comparable previously reported tungsten–silica catalysts.

2026-01-01T00:00:00Z Delawary, Ahmad Reshad Bubulinca, Constantin Kazantseva, Natalia E. Sáha, Petr Le, Quoc Bao Gupta, Ram K. Kiefer, Rudolf http://hdl.handle.net/10563/1012848 2026-07-24T14:23:17Z 2026-01-01T00:00:00Z

Asymmetric supercapacitor based on biomass-derived carbon electrodes functionalized with NdFeB Delawary, Ahmad Reshad; Bubulinca, Constantin; Kazantseva, Natalia E.; Sáha, Petr; Le, Quoc Bao; Gupta, Ram K.; Kiefer, Rudolf Supercapacitors (SCs) are highly attractive energy storage devices, and modern research is focused on using waste materials to reduce environmental impact. This study processed biowaste from local brewery production to produce a highly specific mesoporous activated carbon (AC) for SC electrode scaffolds. Polyaniline (PANI) was synthesized and incorporated into the AC scaffold, thereby enhancing performance. The AC and PANI combination (ACP) achieved a specific capacitance of 173.7 F/g at 1 A/g, with 92% retention after 5000 cycles. Using NdFeB (ACN) particles, the anode showed a specific capacitance of 127 F/g and over 99% retention. An asymmetrical ACN//ACP cell demonstrated promising performance with 70% efficiency. This study highlights the potential of using biowaste for high-performance SC electrodes and the effective synergy between AC and PANI.

2026-01-01T00:00:00Z Paračková, Mária Pechancová, Viera Sáha, Petr Oriňáková, Renáta http://hdl.handle.net/10563/1012851 2026-07-24T14:23:17Z 2026-01-01T00:00:00Z

Evaluating environmental and economic perspectives of hybrid energy storage systems: A review Paračková, Mária; Pechancová, Viera; Sáha, Petr; Oriňáková, Renáta The escalating global challenges have driven significant shifts toward cleaner energy solutions, many of which rely on energy storage technologies. However, there is currently no single energy storage technology that meets all of the application requirements. To address this, hybrid energy storage systems, which combine two or more types of storage devices, have emerged as a promising solution. To support the sustainable implementation of hybrid energy storage systems, this work provides a comprehensive overview of metrics and factors that influence their financial and environmental impacts. In addition, the article discusses the challenges, recommendations, and future directions in conducting sustainability analyses.

2026-01-01T00:00:00Z Škoda, David Hongmanorom, Plaifa Hanulíková, Barbora Důbravová, Alžběta Cvek, Martin Doroshenko, Iaroslav Pokorný, Tomáš Varaďa, Jan Šimoníková, Lucie Kuřitka, Ivo Debecker, Damien P. http://hdl.handle.net/10563/1012842 2026-07-24T14:23:16Z 2026-01-01T00:00:00Z

CO2 methanation with MOF-derived hierarchically porous spherical carbon nanocomposite incorporating cobalt nanoparticles Škoda, David; Hongmanorom, Plaifa; Hanulíková, Barbora; Důbravová, Alžběta; Cvek, Martin; Doroshenko, Iaroslav; Pokorný, Tomáš; Varaďa, Jan; Šimoníková, Lucie; Kuřitka, Ivo; Debecker, Damien P. In this work, a spherical and hierarchical carbon-based nanocomposite containing dispersed cobalt nanoparticles is introduced. The preparation of this material is based on a facile microwave-assisted synthesis of a cobalt-based metal-organic framework containing a 2,6-naphthalene dicarboxylic linker (labeled as NDC) and its subsequent carbonization at either 600 °C or 700 °C in an argon atmosphere. The resulting materials exhibit unique morphology and feature small Co nanoparticles with sizes of about 3.1 and 6.0 nm, respectively, evenly dispersed on the carbon matrix. In the methanation of carbon dioxide, these CoNDC-derived nanocomposites achieved a methane formation rate of up to 10.5 μmolCH4 gcat−1 s−1 at 350 °C, with 100% selectivity to methane. Such behavior is ascribed to a high content of accessible small metallic cobalt nanoparticles present in the hierarchical structure of CoNDC nanocomposite catalysts, highlighting their promising potential for CO2 utilization in industry.

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