Project title	MXenes-type catalysts for energy production and fine-chemical syntheses (MXeneCAT)
Project Code and number	PN-III-P4-ID-PCE-2020-1532; No. PCE17/2020
Contracting Authority	UEFISCDI
Project Host Institution	University of Bucharest
Run period	04.01.2021-31.12.2023
Total funding	1.198.032,00 lei

PROJECT ACHIEVEMENTS

M-Xene type catalysts for energy production and fine syntheses (MxeneC)

The project "M-Xene type catalysts for energy production and fine syntheses (MxeneC)" aimed at the synthesis of new Mxenes, their exhaustive characterization and catalytic evaluation in two processes of interest: 1) The recovery of CO₂ as polluting waste for the production of hydrocarbons, CO or methanol by catalytic hydrogenation, and 2) synthesis of organic intermediates by coupling alkynes with aliphatic and aromatic amines. The project was carried out in three phases:

- Stage 1 (months 1-12): Synthesis of 2D MXenes as reference and support material; CO₂ hydrogenation reactions as waste for the production of hydrocarbons, CO or methanol through catalytic hydrogenation;

- Stage 2 (months 13-24): Synthesis of MXenes with acid catalytic properties and their catalytic evaluation; Synthesis of MXenes for basic catalyzed reactions and catalytic evaluation

- Stage 3 (months 25-36) Synthesis of catalysts containing grafted atoms (M*= Co, Mn, or Bi)(M*-MXenes) for coupling reactions and selective oxidations; Synthesis of metal nanoparticles uniformly deposited on two-dimensional M-Xene with dimensions below 5 nm.

From the syntheses of M-Xenes resulted: 14 2D M*-MXenes (M=Ti, Zr; M*= Ti, Sc, Zr; X=C,B,N) and 10 M*-MXenes (M=Ti; C) different; 24 structures having in composition Ti, Zr, Sc, Nb and Ta, starting from different precursors synthesized in the laboratory and 12 structure 2D MXenes (Ti-Al and Ti-Ga (M=Ti, Sc, Zr; X=C)-( N)G).

The characterization of these materials was carried out through techniques that allow the highlighting of structural properties such as spectroscopy (FTIR, DRUV-Vis, Raman, XPS), crystallographic analysis (XRD), electron microscopy (TEM, SAED, AFM, SEM) but also textural analysis (adsorption of nitrogen after degassing the samples). Last but not least, the acid-base properties of these materials were evaluated by chemisorption of ammonia and CO₂.

High resolution TEM and SAED images confirming the crystallinity of M-Xenes

The conversion in the coupling of alkynes with aliphatic and aromatic amines proceeded with TON values of the order of 10², which represent very high values for materials with specific surfaces of the order of several m²/g; for the oxidation reactions in the liquid phase of cycloalkanes with alcohols (adamantane to 5-hydroxy-adamantane) the reaction proceeded with a selectivity of 42%; the hydrogenation reactions of CO₂ to hydrocarbons and CO proceeded with TON values of the order of 10³.

With the financial support of this project, 13 articles were published, two of which are still under evaluation, 2 invited conferences were held at "Greencam for tomorrow”, and "Materials for Biomass Summer School", Trondheim, Norway, 2022; 16 oral presentations in representative international conferences.

Research Team:

1. Vasile Parvulescu – director

2. Simona Coman – researcher

3. Madalina Sandulescu – researcher

4. Bogdan Cojocaru – researcher

5. Mara-Alexandra Badea – Master student

6. Maria Ghetu – PhD Student

7. Magdi El Fergani – Postdoc

8. Petcuţă Oana-Adriana- PhD Student

Introdction

2D atomic materials like graphenes elicited a considerable interest in the last decades due to the unique structural and electronic properties, their synthesis from available resources and the very high resistance in various environments. As a consequence their utilization found multiple applications, including catalysis. Integrated in this context, MXenes are a new class of 2D family including transition metal carbides, nitrides, and carbonitrides in which two, three, or four atomic layers of a transition metal (M: Ti, Nb, V, Cr, Mo, Ta, etc.) are interleaved with layers of C and/or N or B. To-date the investigation of MXenes in catalysis is still in an infancy state. Taking this state of the art, the project targets the synthesis of new MXenes through the incarceration, surface modification and plasma treatment, more adapted for catalytic applications. Their design focuses the production of fuels from waste CO2, improvement of the refinery production and synthesis of fine chemicals. Complex catalysts will be produced from sustainable resources (like chitosan or alginate) and elements of the groups 3, 4, 13 and 14 (Ti, Al, Sn, Zr, Ga) of the periodic table. Accordingly, the project will be integrated in several mandatory concepts such as environmental protection, energy reduction and circular economy. With the same aim, the synthesis of fine chemicals will be transferred to flow reactors.

The main objective of this project is the investigation of new MXenes materials specifically designed for catalytic applications and to expand the current level of knowledge in this field through a deeper exploration of their properties in a close correlation to theoretical calculations..

The implementation degree of the project:

Phase I/2021 (04.01.2021–31.12.2021): Synthesis of 2D MXenes as reference and support material (Budget 331532 lei)

In order to achieve this phase, the following activities are carried out:

Activity 1.1. - Synthesis of 2D MXenes as reference and support material

Summary of the research report (Phase I):

The research carried out in this phase aimed primarily to establish the conditions under which M-Xene of some elements from groups III-V B can occur. These syntheses were made starting from both precursors synthesized in the laboratory and from mixed carbides MxAlyC2 (M = element from groups III-V B) purchased from companies.

The experiments performed in the laboratory phase confirmed the synthesis of these M-xenes through the structural analyzes performed in the different stages of the synthesis. Associated with the catalytic applications in which these M-xenes will be investigated, the characterizations performed by Raman and XP spectroscopy at this stage have highlighted a number of properties that may indeed have an important contribution. These are:

i. Peripheral functionalization that is performed in the exfoliation stage of the material; the composition of the exfoliation environment and the influence of the conditions in which these treatments are performed have an important contribution;

ii. The functionalities that can be introduced in this stage and their relative ratio can be reproducibly controlled; their effects can be rationally quantified.

iii. The presence of the element M in oxidation states that can be induced on reproducible synthetic routes; the relative ratio of the elements in these states of valence is important.

iv. Synthesized M-xenon structures have metallic, acidic and basic properties, their weight can be controlled. These properties are recommended as versatile in complex catalytic applications.

Based on these results, the objectives assumed in this phase of the project are considered fulfilled.

Dissemination

Journal Articles

1. Recent progress and prospects in catalytic water treatment, Vasile I. Parvulescu, Florence Epron, Hermenegildo Garcia, Pascal Granger, Chem. Rev., ACCEPTED;

2. Valmet Chiral Schiff-Base Ligands And Their Copper(II) Complexes as Organo, Homogeneous and Heterogeneous Catalysts for Henry, Cyanosilylation and Aldol Coupling Reactions, Arora Z. Eftemie D.-I. Spinciu A. Maxim C. Hanganu A.-M., Tudorache M., Cojocaru B., Pavel O.D., Granger P., Andruh M., Pârvulescu V.I, ChemCatChem, 2021, 13(21), 4634 – 4644;

3. Co−Fe Nanoparticles Wrapped on N Doped Graphitic Carbons as Highly Selective CO₂ Methanation Catalysts Bogdan Jurca, Lu Peng, Ana Primo, Alvaro Gordillo, Vasile I. Parvulescu, and Hermenegildo García: ACS Appl. Mater. Interfaces 2021, 13, 36976−36981;

4. Co-Fe Clusters Supported on N-Doped Graphitic Carbon as Highly Selective Catalysts for Reverse Water Gas Shift Reaction, Peng, L., Jurca, B., Primo, A., Parvulescu, V.I., García, H., ACS Sustainable Chemistry and Engineering, 2021, 9(28), 9264–9272;

5. Engineering hydrogenation active sites on graphene oxide and N-doped graphene by plasma treatment, Magureanu, M., Mandache, N.B., Rizescu, C., Parvulescu, V.I., Garcia, H., Applied Catalysis B: Environmental, 2021, 287, 119962;

6. Improvement of catalytic activity of graphene oxide by plasma treatment, Magureanu, M., Mandache, N.B., Gherendi, F., ...Garcia, H., Parvulescu, V.I., Catalysis Today, 2021, 366, 2–9.

Key and plenary lectures

1. O.D. Pavel, R. Zavoianu, R. Birjega, V.I. Pârvulescu, Tailoring lamellar materials: a crucial key to enhance the catalytic efficiency for the synthesis of fine chemicals, 7th UK Catalysis Conference, 6-8 January 2021, London, United Kingdom.

2. V.I. Pârvulescu, Up-grading biomass processses in the presence of Nb-based catalysts, 2021 International Symposiumon Zeolites and Related Porous Materials, 28-29 September 2021, Qingdao, China.

3. V.I. Pârvulescu, Catalysts in the circular economy concept, Contemporary Solutions for Advanced Materials with High Impact on Society Workshop (CoSolMat) 2021 (Norway-Island-Romania), 11-15 October 2021, Bucharest, Romania

4. V.I. Pârvulescu, Co−Fe Supported on N Doped Graphitic Carbon as Highly Selective Catalysts for Reverse Water Gas Shift and Sabatier Reactions, Indo-French Symposium “Functionalized Materials for Sustainable Catalytic and Related Applications, 26-28 October, Strassburg, France.

5. V.I. Pârvulescu, Catalysis (Catalysts) in the circular economy concept, Zilele Academice Clujene 2021, October 21-22, Cluj-Napoca, Romania.

Oral presentations

1. Z. Arora, D. Eftemie, A. Spinciu, C. Maxim, M. Andruh, V.I. Parvulescu, Symbiotic organo- and metal catalytic enanioselective synthesis of β-nitroalcohols by enantiopure Cu (II) complex anchored on Graphene oxide, in Cutting-Edge Homogeneous Catalysis (CEHC-1), 4-6 th May 2021, Toulouse, France, p.42;

2. M. El Fergani, N. Candu, M. Tudorache, P. Granger, V.I. Parvulescu, S.M. Coman, Nb@graphite-like carbon catalysts synthesis: a new way of humins valorization, 5th EuChemS Conference on Green and Sustainable Chemistry (5th EuGSC), 26th – 29th September 2021;

3. M. E. Fergani, N. Candu, P. Granger, V. I. Parvulescu, S. M. Coman, Catalytic properties of (MOx@Nb and Nb)-zeolites based catalyst in the oxidation of glucose and HMF, WORKSHOP on “WATER IN ZEOLITES“, Liblice, September 19-22, 2021;

4. M. E. Fergani, N. Candu, P. Granger, V. I. Parvulescu, S. M. Coman, Non-precious metal-based magnetic catalysts for the production of diacids, 5th EuGSC European Conference on Green and Sustainable Chemistry, Thessaloniki, September 19-22, 2021.

Phase II/2022 (01.01.2022–31.12.2022): Synthesis of MXenes with acidic catalytic properties and their catalytic evaluation; Synthesis of MXenes for basic catalyzed reactions and catalytic evaluation (Budget 546772 lei)

In continuation of the research carried out in phase 1 (2021), the research in phase 2 (year 2022) followed a different strategy for the synthesis of MXenes. At this stage, the researches were focused on the synthesis of multifunctional materials with catalytic properties in reactions catalyzed by metals, but also by acids and bases, respectively. The investigated mixtures were prepared by thermal treatments, involving the calcination/pyrolysis with a temperature-controlled program of some powder mixtures in stoichiometric ratios. The treatment temperatures were established by a correlation program with structural analysis (mainly by X-ray diffraction, Raman and XPS). Using this strategy, Mxenes were synthesized both in the form of powder and in the form of ceramic or imprinted materials.

2.1. Synthesis of MXenes with acidic catalytic properties and their catalytic evaluation

12 2D MXenes structures in which: i) Ti- was associated with Al and –Ga in a graphitic matrix; these syntheses were correlated with structural characterization (spectroscopy (FTIR, DRUV-Vis, Raman, XPS, EDX), crystallographic analysis (XRD), textural characterization (electron microscopy and nitrogen adsorption-desorption), adsorptive properties (hydrogen chemisorption, ammonia and carbon dioxide); and last but not least with the catalytic evaluation; and ii) Etching Ti-based Mxene simultaneously with their imprinting with F and OH functionalities.

2.2. Synthesis of MXenes for basic catalyzed reactions and catalytic evaluation

12 2D MXenes structures in which: in which Nb, respectively Ta are associated with Al, followed by the same set of characterizations and evaluation. structural characterization (spectroscopy (FTIR, DRUV-Vis, Raman, XPS, EDX), crystallographic analysis (XRD), textural (electron microscopy and nitrogen adsorption-desorption), adsorptive properties (chemosorption of hydrogen, ammonia and carbon dioxide); and catalytic evaluation.

2.3. The behavior of M-xenes in reactions specific to metal catalysts

The specific behavior of metal catalysts was verified in hydrogenation reactions of some nitro-aromatic compounds in the presence of some M-xenes. The capacity of these materials validated by ab initio thermodynamic studies corroborated with phase diagrams derived from microkinetic simulations demonstrated that molecular hydrogen dissociates with almost negligible energy barriers, a fact that corresponds to lower reaction temperatures.

2.4. The behavior of basic M-xene catalysts in oxidation reactions

Ti₂AlN MAX Powder and Ti₃C₂Tx Multistrat Mxene showed catalytic activity in cyclohexene oxidation. Important to note in these cases is the high selectivity for cyclohexenol in relatively mild reaction conditions for cyclohexene and aggressive for hydrogen peroxide. The activity of the catalyst due to the relatively small number of active centers is not high, instead the selectivity is ensured. Doubling the conversion has a negative effect on the selectivity.

Dissemination

Papers – Cumulated FI =118.47

1. M. El Fergani, V.I. Parvulescu et al, Catal. Today, 405-406, 267, 2022. FI = 5.70

2. A. Rendón-Patiño, V.I. Parvulescu et al, ChemCatChem, 14, e202200356, 2022. FI = 5.69.

3. L.Peng, V.I. Parvulescu, H. García et al, iScience, 25, 104252, 2022 ; FI = 6.10.

4. L. Căta, V.I. Parvulescu et al, ACS Appl. Mater. Interfaces, 14, 10428, 2022. FI=9.44

5. V.I. Parvulescu, H. Garcia, P. Granger, Chem. Rev., 122, 2981 – 3121, 2022. FI=72.09

6. I.Podolean, V.I. Parvulescu et al, Catal Today, 2022, 10.1016/j.cattod.2022.08.028.

7. A. Primo, V.I. Parvulescu, H. Garcia et al, J. Catal., 405, 355 – 362, 2022. FI = 8.05

8. I. Podolean, S.M.Coman, C, Bucur, C.Teodorescu, S. Kikionis, E.Ioannou, V. Roussis, A. Primo, H. Garcia, V.I. Parvulescu, Catal. Today, 383, 345 - 357 2022; FI = 5.70.

1 submitted Mxene paper and 3 papers under work

Participation in interntional conferences:

13 oral presentations, 2 posters

1. Z. Arora, D.-I. Eftemie, A. Spinciu, C. Maxim, A.-M. Hanganu, M. Tudorache, B. Cojocaru, O.D. Pavel, P. Granger, M. Andruh, V.I. Pârvulescu, Valmet chiral-base ligands and their copper(II) complexes as organo, homogeneous and heterogeneous catalysts for Henry, cyanosilylation and aldol coupling reactions, 4^th HC3A Meeting, Barcelona, 20^th - 21^st January 2022 (ORAL PRESENTATION).

2. J. Barauna, T. M. García, M. Magureanu, V.I. Parvulescu, Plasma-liquid catalysis for CO2 conversion, SICT 2022 / PlasmaTech 2022 / Tribology 2022 Joint Conferences, 27-29 April 2022, Barcelona, Spain (ORAL PRESENTATION).

3. B. Cojocaru, R. Mihailescu, N. Guzo, O.D. Pavel, S. Ion, M. Tudorache, S. Coman, V.I. Parvulescu, Hybrid Organic-Inorganic Magnetic Supramolecular Composites with Adsorption and Photocatalytic Degradation Capabilities of Antibiotics Under Solar Light, The 27th North American Catalysis Society Meeting, May 22-27, 2022, New York (USA) (ORAL PRESENTATION).

4. O.D. Pavel, B. Cojocaru, B.C. Jurca, F. Teodorescu, R. Zăvoianu, V.I. Pârvulescu, Eco-Friendly Mechano-Chemical Route for the Synthesis of Layered Double Hydroxides and Their Behavior in Cyanoethylation, Selective Oxidation and Dehydration-Cyclization Reactions, The 27th North American Catalysis Society Meeting, May 22-27, 2022, New York (USA) (ORAL PRESENTATION)

5. A. Primo_, L. Peng, B. Jurca, V.I. Parvulescu, H. Garcia, Highly Selective Water Gas Shift Reaction over Co−Fe Clusters Supported on N‑Doped Graphitic Carbon, The 27th North American Catalysis Society Meeting, May 22-27, 2022, New York (USA).

6. S. Ion, M. Sandulescu, V.I. Parvulescu, Attempts in Lignin derivatization via biocatalysis, LignoCOST Lignin conference, 1-3 June, 2022, Wageningen (NL) (ORAL PRESENTATION).

7. Kuncser, N. Iacob, P. Palade, G. Schinteie, C. Comanescu, S.M. Coman, V.I. Parvulescu, Specific information on catalytic behavior revealed by Mӧssbauer spectroscopy and magnetometry, 13th International Symposium of The Romanian Catalysis Society, RomCat 2022, June 22-24, 2022, Băile Govora, Romania (ORAL PRESENTATION).

8. M.El. Fergani, I. Podolean, S.M. Coman, V.I. Parvulescu, N. Candu, Selective oxidation of glucose over transitional metal oxides based magnetic core-shell nanoparticles 13th International Symposium of The Romanian Catalysis Society, RomCat 2022, June 22-24, 2022, Băile Govora, Romania (ORAL PRESENTATION).

9. S. Ion, M. Tudorache, V.I. Parvulescu, Biocatalysis as a green route for lignin derivatization, 13th International Symposium of The Romanian Catalysis Society, RomCat 2022, June 22-24, 2022, Băile Govora, Romania (ORAL PRESENTATION).

10. Z. Arora, D.-I. Eftemie, A. Spinciu, C. Maxim, A.-M. Hanganu, M. Tudorache, B. Cojocaru, O.D. Pavel, P. Granger, M. Andruh1, V.I. Pârvulescu, Valmet chiral-base ligands and their copper(II) complexes as organo, homogeneous and heterogeneous catalysts for Henry, cyanosilylation and aldol coupling reactions, 13th International Symposium of The Romanian Catalysis Society, RomCat 2022, June 22-24, 2022, Băile Govora, Romania (ORAL PRESENTATION).

11. M.-A. Badea, B.Cojocaru, E.E. Jacobsen, V.I. Parvulescu, S.M. Coman, Catalytic production of amino acids from biomass-derived intermediates, 13th International Symposium of The Romanian Catalysis Society, RomCat 2022, June 22-24, 2022, Băile Govora, Romania (ORAL PRESENTATION).

12. M.-El Fergani, N. Candu, M. Tudorache, P. Granger, V.I. Parvulescu, S.M. Coman, From humins wastes to highly efficient Nb@graphite-like carbon catalysts: An exemplification of the circular economy concept, TOCAT 9, July 24-29, 2022, Fukuoka, Japan (ORAL PRESENTATION).

13. A. Primo, L. Peng, B. Jurca, V.I. Parvulescu, H. Garcia, Highly selective CO2 methanation over Co-Fe nanoparticles wrapped on N-doped graphitic carbons catalysts, TOCAT 9, July 24-29, 2022, Fukuoka, Japan (ORAL PRESENTATION).

14. P. Granger, J.-P. Dacquin, S. Troncea, V.I. Parvulescu, Peculiar Pd-support interaction in catalytic water denitrification: Impact of the preparation method of Ce_xZr_1-xO₂ support, TOCAT 9, July 24-29, 2022, Fukuoka, Japan (ORAL PRESENTATION).

15. A. Primo, L. Peng, B. Jurca, V.I. Parvulescu, H. Garcia, Highly selective RWGSs reaction over Co-Fe clusters supported on N-doped graphitic carbon, TOCAT 9, July 24-29, 2022, Fukuoka, Japan.

Phase III/2023 (01.01.2023-31.12.2023): Synthesis of "single" atom catalysts (M*) (M*-MXenes) and metal nanoparticles with sizes below 5 nm uniformly dispersed on two-dimensional MXenes and their catalytic evaluation (Buget 319728 lei).

Stage results: Synthesis of 14 2D M*-MXenes (M=Ti, Zr; M*= Co, Mn, Bi) (M=Ti, Sc, Zr; X=C,B,N) and 10 M*-MXenes (M=Ti; M*= Co, Mn, or Bi) structures; Structural characterization (spectroscopy (FTIR, DRUV-Vis, Raman, XPS), crystallography (XRD and microscopy) and textural characterization.

Activity: Synthesis of "single" atom catalysts (M*) (M*-MXenes) and metal nanoparticles with sizes below 5 nm uniformly dispersed on two-dimensional MXenes and their catalytic evaluation.

Dissemination

Articles

1. M. Bordeiasu, A. Ejsmont, J. Goscianska, B. Cojocaru, V.I. Parvulescu, S.M.Coman, Simona M.,Catalytic oxidation of biomass-derived 5-hydroxymethylfurfural to 5-hydroxymethyl-2-furancarboxylic acid by Co-based MOFs, Appl. Catal. A: General, 2023, 657, 119147. FI=5.72.

2. C. Rizescu, M. El Fergani, D.-I. Eftemie, B. Cojocaru, D. Popescu, M. Andruh, V.I. Parvulescu, Liquid phase oxidation of alkenes and glycerol with molecular oxygen over mixed-ligand copper(II) complexes grafted on GO as catalysts, Appl. Catal. A: General, 2023, 66, 119302. FI=5.72.

3. I. Podolean, B. Cojocaru, V.I. Pârvulescu, M. Mazur, S. Abdi, J. Čejka, Synthesis of lactide from L-Lactic acid over iso-reticular zeolites derived from Al-UTL, Appl. Catal. A: General, 2023, 66, 119379. FI=5.72.

Up-to-date information about articles:

4. Recent Progress and Prospects in Catalytic Water Treatment, Vasile I. Parvulescu, Florence Epron, Hermenegildo Garcia, Pascal Granger, Recent progress and prospects in catalytic water treatment, Chem. Rev. 2022, 122, 3, 2981–3121.

5. Monica Magureanu, N.B. Mandache, C. Rizescu, Cristina Bucur, Bogdan Cojocaru, Isabela C. Man, Ana Primo, Vasile I. Parvulescu, Hermenegildo Garcia, Engineering hydrogenation active sites on graphene oxide and N-doped graphene by plasma treatment, Applied Catalysis B: Environmental 2021,Volume 287, 119962.

6. M. Magureanu, N.B. Mandache, F. Gherendi, C. Rizescu, B. Cojocaru, A. Primo, H. Garcia, V.I. Parvulescu, Improvement of catalytic activity of graphene oxide by plasma treatment, Catalysis Today 2021, Volume 366, 2-9.

7. Lu Peng, Bogdan Jurca, Ana Primo, Alvaro Gordillo, Vasile I. Parvulescu, Hermenegildo García, Co–Fe Clusters Supported on N-Doped Graphitic Carbon as Highly Selective Catalysts for Reverse Water Gas Shift Reaction, ACS Sustainable Chem. Eng. 2021, 9, 28, 9264–9272.

Conferences

1. L. Peng, B. Jurca, A. Primo, A. Gordillo, H. Garcıa1, V.I. Parvulescu, High C2-C4 selectivity in CO2 hydrogenation by particle size control of Co-Fe alloy nanoparticles wrapped on N-doped graphitic carbon, 15th European Congress on Catalysis, EUROPACAT2023, August 27-September 1, 2023, Prague, Czech Republic (ORAL PRESENTATION)

2. O.D. Pavel, B.-C. Jurca, R. Zăvoianu, R. Bîrjega, B. Cojocaru, V.I. Pârvulescu, Organic alkalis as an alternative for eco-friendly mechano-chemical synthesis of Layered Double Hydroxides-type catalysts, 15th European Congress on Catalysis, EUROPACAT2023, August 27-September 1, 2023, Prague, Czech Republic (ORAL PRESENTATION)

PhD Thesys:

Cross coupling catalyzed reactions on MOF, CFP and PAF ensembles, Maria Ghetu, 2023, - resignation and interruption of doctoral studies.

Titlul proiectului	Catalizatori de tip MXenes pentru producerea de energie și sinteze chimice fine (MXeneCAT)
Codul si numarul proiectului	PN-III-P4-ID-PCE-2020-1532; No. PCE17/2020
Autoritatea contractanta	UEFISCDI
Institutia gazda a proiectului	Universitatea din Bucuresti
Perioada de derulare	04.01.2021-31.12.2023
Finantarea totala	1.198.032,00 lei

Rezultate obtinute

Catalizatori de tip M-Xene pentru producerea de energie si sinteze fine (MxeneC)

Proiectul « Catalizatori de tip M-Xene pentru producerea de energie si sinteze fine (MxeneC)» a avut drept scop sinteza de Mxene noi, caracterizarea lor exhaustiva si evaluarea catalitica in doua procese de interes: 1) Valorificarea CO₂ ca deseu poluant pentru producerea de hidrocarburi, CO sau metanol prin hidrogenare catalitica, si 2) sinteza de intermediari organici prin cuplarea alchinelor cu amine alifatice si aromatice. Proiectul a fost derulat in trei faze:

- Etapa 1 (lunile 1-12): Sinteza de 2D MXenes ca material de referinta si suport; Reactii de hidrogenare a CO₂ ca deseu pentru producerea de hidrocarburi, CO sau metanol prin hidrogenare catalitica;

- Etapa 2 (lunile 13-24) : Sinteza de MXenes cu proprietati catalitice acide si evaluarea lor catalitica; Sinteza de MXenes pentru reactii catalizate bazic si evaluarea catalitica ;

- Etapa 3 (lunile 25-36) Sinteza de catalizatori continand atomi grefati (M^*= Co, Mn, sau Bi)(M^*-MXenes) pentru reactii de cuplare si oxidari selective si (II) Sinteza nanoparticulelor de metal depuse uniform pe M-Xene bidimensionale cu dimensiuni sub 5 nm.

Din sintezele de M-Xene au rezultat 14 structuri 2D M^*-MXenes (M=Ti, Zr; M^*= Ti, Sc, Zr; X=C,B,N) si 10 M*-MXenes (M=Ti; C) diferite; 24 structuri avand in compozitie Ti, Zr, Sc, Nb si Ta pornind de la diferiti precursori sintetizati in laborator si 12 structuri 2D MXenes (Ti-Al si Ti-Ga (M=Ti, Sc, Zr; X=C)-(N)G).

Caracterizarea acestor materiale s-a realizat prin tehnici care permit evidentierea proprietatilor structurale precum spectroscopie (FTIR, DRUV-Vis, Raman, XPS), analiza cristalografica (XRD), microscopie electronica (TEM, SAED, AFM, SEM) dar si analiza texturala (adsorbtie de azot dupa degazarea probelor). Nu in ultimul rand s-au evaluat proprietatile acido-bazice ale acestor materiale prin chemisorbtie de amoniac si CO₂.

Imagini de inalta rezolutie prin TEM si SAED confirmand cristalinitatea de M-Xenelor

Conversia in cuplarea alchinelor cu amine alifatice si aromatice a decurs cu valori TON de ordinul a 10² ceea ce reprezinta valori foarte ridicate pentru materiale cu suprafete specifice de ordinul a cativa m²/g, pentru reactiile de oxidare in faza lichida ale cicloalcanilor la alcooli (adamantan la 5-hidroxi-adamantan) reactia a decurs cu o selectivitate de 42% iar valorile TOF in reactiile de hidrogenare ale CO₂la hidrocarburi si CO au decurs cu valori TON de ordinul a 10³.

Cu sustinerea financiara a acestui proiect au fost publicate 13 articole, doua fiind inca in evaluare, au fost tinute 2 conferinte invitate la “Greencam for tomorrow, si "Materials for Biomass Summer School", Trondheim, Norvegia, 2022 ; 16 prezentari orale in Conferinte internationale reprezentative.

Echipa de cercetare:

1. Vasile Parvulescu – director

2. Simona Coman – cercetatoer

3. Madalina Sandulescu – cercetator

4. Bogdan Cojocaru – cercetator

5. Mara-Alexandra Badea – masterand

6. Maria Ghetu – doctorand

7. Magdi El Fergani – postdoc

8. Petcuţă Oana-Adriana- PhD Student

Rezumatul proiectului

Materialele atomice 2D precum grafenele au suscitat un interes considerabil în ultimele decenii datorită proprietăților structurale și electronice unice, sintezei lor din resursele disponibile și rezistenței foarte mari în diverse medii. Ca o consecință, utilizarea lor a găsit mai multe aplicații, inclusiv cataliză. Integrate în acest context, MXenele reprezintă o nouă clasă de materiale 2D care include carburi, nitruri și carbonitruri ale metalelor tranziționale în care două, trei sau patru straturi atomice ale unui metal de tranziție (M: Ti, Nb, V, Cr, Mo, Ta) , etc.) sunt intercalate cu straturi de C și/sau N sau B. Până în prezent, investigarea MXenelor în cataliză este încă într-o stare incipientă. Luând acest stadiu al tehnicii, proiectul vizează sinteza de noi MXene prin incorporare, modificarea suprafeței și tratarea cu plasmă, mai adaptate pentru aplicații catalitice. Designul lor se concentrează pe producția de combustibili din CO₂ rezidual, îmbunătățirea producției din rafinării și sinteza de chimicale fine. Catalizatorii complecși vor fi produși din resurse durabile (cum ar fi chitosan sau alginat) și elemente din grupele 3, 4, 13 și 14 (Ti, Al, Sn, Zr, Ga) ale tabelului periodic. În consecință, proiectul va fi integrat în mai multe concepte obligatorii precum protecția mediului, reducerea energiei și economia circulară. Cu același scop, sinteza de chimicale fine va fi transferată în reactoare cu flux.

Obiectivul principal al acestui proiect este investigarea noilor materiale MXene special concepute pentru aplicații catalitice și extinderea nivelului actual de cunoștințe în acest domeniu printr-o explorare mai profundă a proprietăților acestora într-o strânsă corelație cu calculele teoretice.

Gradul de implementare a proiectului:

Faza I/2021 (04.01.2021–31.12.2021): Sinteză MXene 2D ca material de referință și suport (Buget 331532 lei)

Pentru realizarea acestei etape se desfasoara urmatoarele activitati:

Activitatea 1.1. - Sinteza MXenelor 2D ca material de referință și suport

Rezumatul raportului de cercetare (Faza I):

Cercetările efectuate în această fază au vizat în primul rând stabilirea condiţiilor în care poate apărea M-Xene al unor elemente din grupele III-V B. Aceste sinteze au fost realizate pornind atât de la precursori sintetizați în laborator, cât și din carburi mixte M_xAl_yC₂ (M = element din grupele III-V B) achiziționate de la firme.

Experimentele efectuate în faza de laborator au confirmat sinteza acestor M-xene prin analizele structurale efectuate în diferitele etape ale sintezei. Asociate cu aplicațiile catalitice în care vor fi investigate aceste M-xene, caracterizările efectuate prin spectroscopie Raman și XP în această etapă au evidențiat o serie de proprietăți care pot avea într-adevăr o contribuție importantă. Acestea sunt:

i. Functionalizarea periferica care se realizeaza in etapa de exfoliere a materialului; o contribuție importantă o au compoziția mediului de exfoliere și influența condițiilor în care se efectuează aceste tratamente;

ii. Funcționalitățile care pot fi introduse în această etapă și raportul lor relativ pot fi controlate reproductibil; efectele lor pot fi cuantificate raţional.

iii. Prezența elementului M în stări de oxidare care pot fi induse pe căi sintetice reproductibile; raportul relativ al elementelor în aceste stări de valență este important.

iv. Structurile M-Xenelor sintetizate au proprietăți metalice, acide și bazice, proportia lor poate fi controlată. Aceste proprietăți sunt recomandate ca fiind versatile în aplicații catalitice complexe.

Pe baza acestor rezultate, obiectivele asumate în această fază a proiectului sunt considerate îndeplinite.

Diseminarea rezultatelor

Articole in jurnale de specialitate

1. Recent progress and prospects in catalytic water treatment, Vasile I. Parvulescu, Florence Epron, Hermenegildo Garcia, Pascal Granger, Chem. Rev., ACCEPTED;

6. Improvement of catalytic activity of graphene oxide by plasma treatment, Magureanu, M., Mandache, N.B., Gherendi, F., ...Garcia, H., Parvulescu, V.I., Catalysis Today, 2021, 366, 2–9.

Prelegeri cheie și plenare

2. V.I. Pârvulescu, Up-grading biomass processses in the presence of Nb-based catalysts, 2021 International Symposiumon Zeolites and Related Porous Materials, 28-29 September 2021, Qingdao, China.

5. V.I. Pârvulescu, Catalysis (Catalysts) in the circular economy concept, Zilele Academice Clujene 2021, October 21-22, Cluj-Napoca, Romania.

Prezentari orale

Faza II/2022 (01.01.2022–31.12.2022): Sinteza de MXene cu proprietati catalitice acide si evaluarea lor catalitica; Sinteza de MXene pentru reactii catalizate bazic si evaluarea catalitica (Buget 546772 lei)

In continuarea cercetarilor efectuate in cadrul fazei 1 (2021), cercetarile la faza 2 (anul 2022) au urmarit o strategie diferita de sinteza a MXene-lor. In aceasta etapa cercetarile au fost focusate asupra sintezei de materiale multifunctionale cu proprietati catalitice in reactii catalizate de metale, dar si de acizi si respectiv de baze. Mxenele investigate s-au preparat prin tratamente termice, implicand calcinarea/piroliza cu program controlat de temperatura a unor amestecuri de pulberi in rapoarte stoichiometrice. Temperaturile de tratament s-au stabilit printr-un program de corelare cu analiza structurala (in principal prin difractie de raze X, Raman si XPS). Folosind aceasta strategie au fost sintetizate atat Mxene sub forma de pulbere cat si sub forma de materiale ceramice sau amprentate.

2.1. Sinteza de MXenes cu proprietati catalitice acide si evaluarea lor catalitica

12 structuri 2D MXenes in care: i) Ti- a fost asociat cu Al si –Ga intr-o matrice grafitica; aceste sinteze au fost corelate cu caracterizarea structurala (spectroscopie (FTIR, DRUV-Vis, Raman, XPS, EDX), analiza cristalografica (XRD), caracterizarea texturala (microscopie electronica si adsorbtie-desorbtie de azot), proprietatile adsorptive (chemosorbtie de hidrogen, amoniac si dioxid de carbon); si nu in ultimul rand cu evaluarea catalitica; si ii) Etching Ti-based Mxene concomitent cu amprentarea acestora cu functionalitati F si OH.

2.2. Sinteza de MXenes pentru reactii catalizate bazic si evaluarea catalitica

12 structuri 2D MXenes in care: in care Nb, respectiv Ta sunt asociati Al, urmat de acelasi set de caracterizari si evaluare. caracterizare structurala (spectroscopie (FTIR, DRUV-Vis, Raman, XPS, EDX), analiza cristalografica (XRD), texturala (microscopie electronica si adsorbtie-desorbtie de azot), proprietati adsorptive (chemosorbtie de hydrogen, ammoniac si dioaxid de carbon); si evaluare catalitica.

2.3. Comportamentul M-xenelor in reactii specifice catalizatorilor metalici

Comportamentul specific catalizatorilor metalici a fost verrificat in reactii de hidrogenare ale unor compusi nitro-aromatici in prezenta unor M-xene. Capacitatea acestor materiale validata prin studii termodinamice ab initio corroborate cu diagrame de faza derivate din simulari microcinetice a demonstrat ca hidrogenul molecular disociaza cu bariere de energie aproape neglijabile, fapt care corespunde unor temperaturi de reactie coborate.

2.4. Comportamentul catalizatorilor M-xene bazice in reactii de oxidare

Ti₂AlN MAX Pulbere si Ti₃C₂Tx Mxene Multistrat au prezentat activitate catalitica in oxidarea ciclohexenei. Important de notat in aceste cazuri este selectivitatea ridicata la ciclohexenol in conditii de reactie relativ blande pentru ciclohexena si agresive pentru apa oxigenata. Activitatea catalizatorului prin numarul relativ mic de centrii activi nu este ridicata in schimb selectivitatea este asigurata. Dublarea conversiei are efect negativ asupra selectivitatii.

Diseminare rezultate

Factor total cumulat pentru 8 articole FI cumulat=118.47