Keynote Lectures

KN1

Catalytic treatment of environmental contaminants of European Union concern

Adrián M.T. Silva

Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal. E-mail: adrian@fe.up.pt

We are facing new challenges with the spread of organic chemical micropollutants in water bodies. Water is a highly sensitive natural resource and priority substances (PSs) and contaminants of emerging concern (CECs) have been found in the aquatic environment, often up to μg L-1 levels. In this context, Directive 2013/39/EU was launched to update the water framework policy in Europe, emphasizing the need to develop new water treatment technologies to deal with this problem. 1 In addition, a dynamic watch list of substances was defined to allow targeted EU-wide monitoring of specific compounds of possible concern, the most recent version being included in Decision 2020/1161 to collect data supporting prioritization in future revisions of the PSs list.2 It is thus clear that alternatives are required to minimize water contamination, aiming at enhanced environmental and life quality in Europe.However, the problem isfar to be solved, these pollutants being detected in effluents of urban wastewater treatment plants, seawater and even in drinking water. 1-3 An overview of the author’s experience in the monitoring of these micropollutants, and in the synthesis, characterization and application of active and stable catalysts, including catalytic membranes, will be discussed in this lecture by considering different water/wastewater treatment technologies. Special emphasis will be placed on the use of carbon materials and their respective functionalization, since carbon materials with no added metals can be used as active catalysts in some of these processes. Three major questions will be answered: Which is the appropriate surface chemistry? What about textural properties? What type(s) of carbon material(s) are best suited in each case? The aim is to reveal how to perform a meticulous tailoring of the surface chemistry (surface oxidation and heteroatom doping) and texture (surface area, pore size, distance between adjacent sheets/stacks) of carbon materials with different dimensionalities. Besides the oxidation of EU-relevant chemical micropollutants by generating highly reactive radicals from O3, persulfate activation or H2O2 (added or photocatalytically generated in-situ), water disinfection (eliminating antibiotic resistant bacteria and their genes) will also be discussed.4-6

References

[1] Ribeiro, A. R.; Nunes, O.C.; Pereira, M.F.R.; Silva, A.M.T.; Environ. Int., 2015, 75, 33. [2] Barbosa, M.; Moreira, F.F.N.; Ribeiro, A.R.; Pereira, M.F.R.; Silva, A.M.T.; Water Res., 2016, 94, 257. [3] Sousa, J.C.G.; Ribeiro, A.R.; Barbosa, M.O.; Pereira, M.F.R.; Silva, A.M.T.; J. Hazard. Mater., 2018, 344, 146. [4] Pedrosa, M.; Drazic, G.; Tavares, P.B.; Figueiredo, J.L.; Silva, A.M.T.; Chem. Eng. J., 2019, 369, 223. [5] Torres-Pinto, A.; Sampaio, M.J.; Silva, C.G.; Faria, J.L.; Silva, A.M.T.; Appl. Catal. B: Environ., 2019, 252, 128. [6] Vieira, O.; Ribeiro, R.S.; Pedrosa, M.; Ribeiro, A.R.L.; Silva, A.M.T., Chem. Eng. J., 2020, 402, 126117.

Acknowledgments: This work was financially supported by project NORTE-01-0145-FEDER-031049 (InSpeCt) funded by FEDER funds through NORTE 2020 - Programa Operacional Regional do NORTE and by national funds (PIDDAC) through FCT/MCTES (PTDC/EAM-AMB/31049/2017), and by project NORTE-01-0145-FEDER-000069 (Healthy Waters) supported by NORTE 2020 under the PORTUGAL 2020 Partnership Agreement through FEDER. The scientific collaboration under project Base-UIDB/50020/2020 and Programmatic-UIDP/50020/2020 Funding of LSRE-LCM, funded by national funds through FCT/MCTES (PIDDAC), is also acknowledged.

KN2

The role of porous materials as supports for transition metal-scorpionate catalysts

Luísa M.D.R.S. Martins

Centro de Química Estrutural and Departmento de Engenharia Química, Instituto Superior Técnico, Universidade de Lisboa, Portugal. E-mail: luisammartins@tecnico.ulisboa.pt

Only chemical innovations conducted in a sustainable way can allow some progress in achieving the United Nations Sustainable Development Goals. Challenges concerning the search for sustainable conditions, namely, involving the class of C-scorpionate metal catalysts (Figure 1) are addressed. In general, the immobilization of the C-scorpionate catalysts on solid supports (zeolites1,2 or functionalized carbon materials1,3) revealed to be a good strategy to improve the catalytic protocols for alkane, alkene, or alcohol oxidations.

Figure 1. General structure of a C-scorpionate compound.

This presentation aims to highlighting the important link between heterogeneous catalysis and sustainability and encourage synthetic chemists in using immobilized catalysts.

R’

N N R N R’ N

C

N N R’

References

[1] Martins, L.M.D.R.S.; Coord. Chem. Rev., 2019, 396, 89. [2] Van-Dúnem, V.; Carvalho, A.P.; Martins, L.M.D.R.S.; Martins, A.; ChemCatChem, 2018, 10, 4058. [3] Duarte, T.A.G.; Carvalho, A.P.; Martins, L.M.D.R.S.; Catal. Today, 2020, 357, 56-63.

Acknowledgments: The author warmly thanks all co-workers and students for their contribution for the presented work and also acknowledges Centro de Química Estrutural and the financial support of Fundação para a Ciência e Tecnologia (UIDB/00100/2020).

Graphene and its outstanding applications

Rui P.F.F. da Silva, Bruno R. Figueiredo, Vitor Abrantes, João Rodrigues, S. Barros-Silva, Cristina Correia

Graphenest S.A., Lugar da Estação, Edifício Vouga Park, 3740-070 Paradela do Vouga, Portugal. E-mail: ruisilva@graphenest.com

Since it was first discovered in 2004, graphene was labeled as a wonder material due to its enormous potential of bringing new disruptive products to our everyday lives. However, the development of such products and its integration into the industry has revealed to be a harsh path due to the lack of know-how and the initial market flood from dubious graphene sources. Graphenest, through its sustainable proprietary graphene production technology, has positioned itself as a technology provider of graphene-based solutions such as (i) enhanced epoxy resin for mechanical reinforced composites; (ii) electrically conductive coatings for screenprinted circuitry; (iii) capacitive sensors for touch screen applications; (iv) Thermal interface materials (TIMs) for heat dissipation and power management; and (v) ElectroMagnetic Interference (EMI) Shielding coatings and polymers for application on future communication networks. Graphenest, through graphene, the best-in-class material for shielding purposes at the highfrequency range (5G and 6G), has paved the way for the development of graphene-based plastics and coatings that are bestsuitedfor EMI Shielding applications where the absorption mechanism is the prominent. Graphene and related materials are considered the most promising and effective candidates for effective EMI shielding because of their excellent electrical properties, extremely high specific surface area, and unprecedented strength to weight ratio.

Figure 1. Graphenest interested applications and know-how.

TIMs Batteries

Graphene Sensors

EMI Shield Composites

Coatings

KN4

Advances in biomass-derived microporous carbons: development and applications

Vânia Calisto

Department of Chemistry & Center for Environmental and Marine Studies (CESAM), University of Aveiro, 3810-193 Aveiro, Portugal. E-mail: vania.calisto@ua.pt

Microporous carbons and, in particular, activated carbons (AC) are massively applied in a large number of well-established and emergent environmental problems, with a global market that has been continuously growing, being close to 5450 kilotons in 2021. Currently available commercial options strongly rely on non-renewable fossil sources as AC precursors (such as bituminous coal, lignite coal and peat), which raises concerns due to possible mid/long-term shortage of raw materials and the sustainability of these fossil-based carbons. In this context, finding valid and reliable alternative precursors would trigger a significant increase in the greenness scale of these widely applied materials. This communication presents recent advances in the use of carbon-rich residual biomass from industrial activities (namely, paper and brewing industries) for the development of highly microporous carbons, with subsequent application in advanced water treatment. Along with the advantages of replacing non-renewable sources for AC production, the use of residual biomass contributes to the valorization and sustainable management of such residues, often significantly underutilized before disposal. Residual biomass from the referred industries were subjected to thermal and chemical treatments of different complexity, with strong focus on the precursors adequacy to repeatedly achieve materials with stable characteristics and on the evaluation of their potential to obtain microporous carbons with distinct key features through structured experimental designs. In this sense, this research was focused on the development of biochar (obtained by pyrolysis); photocatalystcoated biochar (titanium dioxide incorporation onto the biochar); powdered AC (pyrolysis combined with chemical activation); granular AC (pyrolysis combined with chemical activation and agglomeration); and functionalized AC (pyrolysis combined with chemical activation and followed by grafting functionalization or magnetization). Along with conventional heating for the conversion of the biomass into a microporous carbon net, microwave-assisted pyrolysis was applied in view of investing in more sustainable production routes, by optimizing low-energy processes, minimizing the use of reagents, and promoting after-use regeneration strategies. The developed materials were fully characterized, addressing their chemical, physical and textural properties, and their correlation with production conditions. Then, the efficiency of these materials in the removal of pharmaceuticals from water, foreseeing their application in the advanced treatment of wastewater, was evaluated either in single or competitive conditions, batch, or continuous modes. This research made a significant contribution to encourage the introduction of wastes in the productive chain, deconstructing the idea that secondary raw materials necessarily result in microporous carbons with inferior properties.

Acknowledgments: This work was funded by FEDER through COMPETE 2020 and national funds through Fundação para a Ciência e Tecnologia (FCT) by the research projects RemPharm - PTDC/AAG-TEC/1762/2014 and WasteMAC POCI-01-0145-FEDER-028598 and by the L’Oréal Foundation through the “L’Oréal Medal of Honour for Women in Science”. Thanks, are also due to FCT/MCTES for the financial support to UIDP/50017/2020+UIDB/50017/2020, through national funds. Vânia Calisto thanks FCT for the Scientific Employment Stimulus support (CEECIND/00007/2017).

KN5

Polymer biocomposites with functionalized graphene for biomedical applications

Maria C. Paivaa, Magda Silvaa,b, Daniela Diasa,b, Eunice Cunhac, M. Fernanda Proençad , Natália M. Alvesb,e

aInstitute for Polymers and Composites, University of Minho, 4800-058 Guimarães, Portugal. bI3B´s Research Group, Biomaterials, Biodegradables and Biomimetics, University of Minho, AvePark-Parque de Ciência e Tecnologia, 4805-017 Barco, Taipas, Guimarães, Portugal. cINEGI, Rua Dr. Roberto Frias, 400, 4200-465 Porto. dCenter of Chemistry, University of Minho, 4710-057 Braga, Portugal. eICVS/3B’s, Associative PT Governement Laboratory, Braga/Guimarães, Portugal. E-mail: mcpaiva@dep.uminho.pt

Graphene and few-layer graphene (FLG) materials have great potential in the biomedical field due to their mechanical properties, electrical conductivity and biocompatibility, and are expected to provide cell adhesion and low toxicity. FLG production methods are typically based on liquid-phase exfoliation or oxidation/reduction reactions. The preparation of biopolymer composites with FLG using melt mixing methods is a simple and clean approach for the direct production of three-dimensional scaffolds by Fused Deposition Modelling (FDM). The FLG plays the role of mechanical reinforcement, so that composite properties meet the requirements for medical applications. In the present work two types of chemically functionalized FLG were prepared, and composite scaffolds were produced, as described below: i) Poly(caprolactone) (PCL) and FLG1. FLG1 was prepared by exfoliation of graphite in an aqueous solution of a pyrene derivative by non-covalent functionalization;1 the FLG1 and PCL pellets were mixed by cryomilling, producing a powder for printing scaffolds by direct melt mixing and FDM on a Bioextruder system (Figure 1 a). ii) Polylactic acid (PLA) and FLG2. FLG2 was obtained by covalent functionalization by the 1,3-dipolar cycloaddition of an azomethine ylide;2 the composites were produced by melt mixing on a lab-scale twin screw extruder, the filaments produced were used for preparation of scaffolds by FDM (Figure 1 b). FLG1 and FLG2 were characterized for their morphology, structure and functionalization yield by scanning electron microscopy, Raman spectroscopy and thermogravimetry. The biocomposites were tested for their mechanical performance by dynamic mechanical analysis, performed in a PBS solution at 37 ºC; scaffold porosity was accessed and degradation studies were carried out. The studies demonstrate the interest of the composites for scaffold production.

a) b)

Figure 1. Scaffolds produced by FDM a) directly on a Bioextruder and b) producing composite filament by twin screw extrusion and then the scaffolds by FDM.

References

[1] E. Cunha, et al.; Nanomaterials, 2018, 8, 675. [2] M. Silva, et al.; RSC Adv., 2017, 7, 27578-27594.

Acknowledgments: Thanks are due to the University of Minho and FCT for funding.

50 Years of catalysis in Portugal

José Luís Figueiredo

LSRE-LCM, Faculty of Engineering, University of Porto, 4200-465 Porto, Portugal. E-mail: jlfig@fe.up.pt

Catalysis, “one of the uniquely important skills of Chemistry”,1 arrived at the Portuguese Universities in the 1970’s, when a few faculty members returned home after completing their PhDs abroad, and started their own research groups in this topic. Luís Sousa Lobo, from the University of Lourenço Marques (in colonial Mozambique), was the pioneer. He obtained his PhD in June 1971 at the Imperial College of Science and Technology (Univ. London) after working with David L. Trimm, and returned to Lourenço Marques in the spring of 1972, where he started teaching catalysis and supervising the research work of Carlos A. Bernardo. Their first results were published in 1974. Then, others followed: M.F. Portela (IST, 1972, after 2 years of research at IFP); J.L. Figueiredo (Imperial College, 1975); Ester F.G. Barbosa and Carlos A. Bernardo (Imperial College, 1977); Fernando Ramôa Ribeiro (Univ. Poitiers, 1980, research carried out at IFP). In the last quarter of the 20th century, research in catalysis developed mainly in Lisbon (IST) and Porto (FEUP). In this communication, we will recall a number of initiatives that stand out during these first 50 years of Catalysis in Portugal.2 The 5th Ibero-American Symposium on Catalysis (Lisbon, 1976) was a landmark event where many international collaborations were forged, which were essential for the consolidation of the emerging Portuguese research groups. The MSc Course on Chemistry of Catalytic Processes was an initiative of CQE/IST (Alberto Romão Dias) where several generations of students were trained in the various aspects of Catalysis since 1981. The first of many NATO Advanced Study Institutes organized in Portugal on catalysis topics took place in Lagos (Catalyst Deactivation, May 1981), and the first Portuguese textbook on Catalysis was published in 1989.3 The Catalysis Division of SPQ was established in 1991; its first scientific meeting (Aveiro, 1993) was attended by 54 participants from 18 research groups. Two years later, the membership of the Catalysis Division of SPQ reached 196 registrations. In May 2004, the Homogeneous Catalysis Coimbra Course was the first of its kind organized in Portugal. Another landmark event was the Integrated Course on Catalysis, organized according to the format proposed by the ERA-Net “ACENET”; it was attended by 50 participants, and took place (mostly) in Coimbra, from 21st April to 30th June, 2006. A Doctoral Program on Catalysis and Sustainability (CATSUS), coordinated by IST, was approved in 2013. Catalysis was the cornerstone of the Chemical Industry during the 20th century. It will surely be a key technology for solving the new challenges ahead.

References

[1] Whitesides, G.M.; Angew. Chem. Int. Ed., 2015, 54, 3196–3209. [2] Figueiredo, J.L.; Catalysis @ FEUP, FEUP Editions, 2020. [3] Figueiredo, J.L.; Ramôa Ribeiro, F.; Catálise Heterogénea, 1st ed., Gulbenkian, 1989.

Acknowledgments: Base-UIDB/50020/2020 and Programmatic-UIDP/50020/2020 funding of LSRE-LCM, by national funds through FCT/MCTES (PIDDAC). .