Exceeding Equilibrium CO2 Conversion by Plasma-Assisted Chemical Looping

We propose and demonstrate an integrated electrified plasma-assisted chemical looping (PACL) process
that yields supra-equilibrium CO2 conversions unattainable with conventional catalysis at temperatures ≪3000 K. CO2 is first dissociated inside plasma into CO/O at supra-equilibrium conversions (up to 60%) at a bulk gas temperature of 773 K and a 403 kJ/mol energy cost. Supra-equilibrium CO2 conversions
(29% on average) are achieved at the reactor outlet by placing a nanostructured CeO2 /Fe2O3 oxygen scavenger, prereduced by H2 plasma, downstream of the plasma zone, to capture produced oxygen species and suppress CO/O recombination. Without plasma-material synergy, such an average CO2 conversion can only be attained at temperatures ≥ 2775 K, according to chemical equilibrium calculations. This concept of plasma-assisted chemical looping allows reaching 3-fold higher conversions than state-of-the-art plasma technologies.


Delikonstantis E., Scapinello M., Singh V., Poelman H., Montesano C., Martini L.M., Tosi P., Marin G. B., Van Geem K. M., Galvita V. V. and Georgios D. Exceeding Equilibrium CO2 Conversion by Plasma-Assisted Chemical Looping. ACS Energy Letters 7, 6, 1896–1902 (2022). https://doi.org/10.1021/acsenergylett.2c00632

FLTPD 2022 – Frontiers in Low Temperature Plasma Diagnostics

The Frontiers in Low Temperature Plasma Diagnostics (FLTPD) workshop is a European event, a continuation of a biennial series that began in 1995 at Les Houches (France). This year the FLTPD XIV is organized by the Atomic and Molecular Physics Group – Department of Physics of the Trento University and the Institute for Plasma Science and Technology of the Consiglio Nazionale delle Ricerche. The 14th edition of FLTPD took place in Levico Terme from Sunday 1st to Thursday 5th, May 2022.

The workshop offers the opportunity to present recent results on plasma diagnostics and aims to bring together experts in low-temperature plasma diagnostics. It is an important and fruitful opportunity for the new generation of plasma scientists to share and discuss the knowledge of these diagnostics with the leading scientists in the field.

You can find further information on the webpage of the event here.

What they say about us

Thank you for organising a terrific conference.

Thank you very much for the superb organization of FLTPD. An excellent mix of interesting talks and friendly discussions in a highly scenic and wonderful place.

Thank you for organizing the conference – it was a marvellous place and outstandingly excellent food and service!

I would like to take the opportunity to thank you for the great conference, the perfect organization and the very nice time in Levico!

Thank you very much for the organization of this excellent and friendly conference.

Moments of FLTPD-XIV

International Scientific Committee
Nader Sadeghi, Université Grenoble Alpes, France – Chair
Uwe Czarnetzki, Ruhr University Bochum, Germany – Vice Chair
Gilles Cartry, Université Aix Marseille, France
Giorgio Dilecce, ISTP-CNR, Italy
Richard Engeln, Eindhoven University of Technology, The Netherlands
František Krčma, Brno University of Technology, Czech Republic
Kirsty Mc Kay, University of Liverpool, UK

Local Organizing Committee
Paolo Tosi, University of Trento – Chair
Giorgio Dilecce, ISTP-CNR – co-Chair
Luca Matteo Martini, University of Trento – co-Chair
Matteo Ceppelli, University of Trento
Cesare Montesano, University of Trento
Olga De Pascale, ISTP-CNR
Paolo Francesco Ambrico, ISTP-CNR

Time-resolved optical emission spectroscopy in CO2 nanosecond pulsed discharges

Nanosecond repetitively pulsed discharges at atmospheric pressure have shown comparatively high performances for CO2 reduction to CO and O2. However, mechanisms of CO2 dissociation in these transNanosecond repetitively pulsed discharges at atmospheric pressure have shown comparatively high performances for CO2 reduction to CO and O2. However, mechanisms of CO2 dissociation in these transient discharges are still a matter of discussion. In the present work, we have used time-resolved optical emission spectroscopy to investigate the CO2 discharge progression from the initial breakdown event to the final post-discharge. We discover a complex temporal structure of the spectrally resolved light, which gives some insights into the underlying electron and chemical kinetics. We could estimate the electron density using the Stark broadening of O and C lines and the electron temperature with C+ and C++ lines. By adding a small amount of nitrogen, we could also monitor the time evolution of the gas temperature using the Second Positive System bands of N2. We conclude that the discharge evolves from a breakdown to a spark phase, the latter being characterised by a peak electron density around 1018 cm−3 and a mean electron temperature around 2 eV. The spark phase offers beneficial conditions for vibrationally enhanced dissociation, which might explain the high CO2 conversion observed in these plasma discharges.


M. Ceppelli*, T.P.W. Salden*, L. M. Martini, G. Dilecce and P. Tosi, Time-Resolved Optical Emission Spectroscopy in CO2 Nanosecond Pulsed Discharges, Plasma Sources Sci. Technol. https://doi.org/10.1088/1361-6595/ac2411 (2021).

*M. Ceppelli and T. P. W. Salden have equally contributed to the paper.

Euregio young researchers award

Luca Matteo Martini was awarded the third prize in the Euregio contest for young researchers. The prize is organized by Tyrol and Trentino-Alto Adige regions. The aim of the initiative is to create a network for the emergence of new ideas.

You can find the webpage of the event here.

The reactivity of methanimine radical cation (H2CNH•+) and its isomer aminomethylene (HCNH2•+) with C2H4

Experimental and theoretical studies are presented on the reactivity of H2CNH•+ (methanimine) and HCNH2•+ (aminomethylene) with ethene (C2H4). Selective isomer generation is performed via dissociative photoionization of suitable neutral precursors and reactive cross sections and branching ratios are measured as a function of photon and collision energies. Differences between isomers’ reactivity are discussed in light of ab-initio calculations on reaction mechanisms. The main products, for both isomers, are H-elimination, most likely occurring from covalently bound adducts (giving c-CH2CH2CHNH+/ CH2NHCHCH2+) and H atom transfer to yield H2CNH2+. The astrochemical implications of the results are briefly addressed.


Sundelin D., Ascenzi D., Richardson V., Alcaraz C., Polášek M., Romanzin C., Thissen R., Tosi P., Žabka J., Geppert W. The reactivity of methanimine radical cation (H2CNH•+) and its isomer aminomethylene (HCNH2•+) with C2H4. Chemical Physics Letters 777, 138677 (2021). https://doi.org/10.1016/j.cplett.2021.138677

CH44 reforming with CO2 in a nanosecond pulsed discharge. The importance of the pulse sequence

The plasma dry reforming reaction of methane with carbon dioxide is investigated in a nanosecond repetitively pulsed discharge, a type of plasma that offers some of the highest performance and non-equilibrium characteristics. The experiment’s purpose was to examine the effect of varying the sequence of high-voltage pulses. We find that when successive pulses are closer than 500 μs, a memory-dominated regime gradually develops, which influences subsequent breakdown events. While reactant conversions increase with the plasma energy, both energy efficiency and conversions increase by shortening the inter-pulse time at the same plasma energy. This finding suggests that plasma power is not the only thing that matters to achieve better performance. How it is delivered can make a significant difference, in particular for CO2, whose conversion doubles at the maximum energy for molecule investigated, 1.6 eV molecule-1.en start writing!


C. Montesano, M. Faedda, L.M. Martini, G. Dilecce, P. Tosi, CH4 reforming with CO2 in a nanosecond pulsed discharge. The importance of the pulse sequence, Journal of CO2 Utilization 49, 101556 (2021).