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In this series of articles, the board members of ChemSusChem discussrecent research articles that they consider of exceptional quality and importance for sustainability.T his entry features Dr.P ieter Bruijnincx, who discusses bio-based approaches to new and existing chemicals for large-scale polymera pplications, highlighting that the development of methodologies to obtain key monomers from biomass leads to new chemistry, aids the transition to am ore sustainable chemical industry, and fostersnew interdisciplinary approaches. New and Drop-in Bio-based ChemicalsNature offers many opportunities for the production of renewable platform molecules (i.e.,b uildingb locks for am ore sustainable chemical industry). Of particulari nterest, in terms of impact,a re those biomass-derivedp latformm olecules that can be used as monomersf or large-scale polymer applications. [1] Indeed, world plastics consumption showsaconsistenta nnual growth, reaching 311Mti n2 014. These polymers are unfortunately stilll argely made from fossil resources. Bio-based polymers do find their way into the market and show faster annual growth rates than the fossil-derived ones, yet stillcontribute to less than 5% of the total production volume. Much research and development efforts are currently being devoted, both in industry and in academia, to develop conversion technology and polymer materials to increasethis share. An obviousincentive of using high-value, renewable monomers for large-scale polymer applications lies in the concomitant reduction of the carbon footprint of the chemical and polymer industry.T he use of renewable resources, such as biomass,also offers another,d istinct opportunity:c hemical diversity.T he high functionalgroup density and overall oxidation state of many of the main components of biomass offer versatility in terms of reactivity and access to chemical structures and compounds that can be much less easily and efficientlym ade from conventionalf ossil resources. The building blocks that can be obtainedf rom biomass can then be classifieda se ither drop-in (i.e.,m olecularly identicalt oc urrent petrochemical-derived monomers) or new monomers. The former hold the advantage of access to existing markets and applications, but need to be ablet oc ompete on price (there being no real premium on 'green'). The latter offer ac ompetitive advantage that is based on performance, rather than on price, but require applicationsa nd markets to be developed.

The electrocatalytic conversion of furanic compounds, i.e. mainly furfural and 5-hydroxymethylfurfural, has recently emerged as a potentially scalable technology for both oxidation and hydrogenation processes because of its highly valuable products. However, its practical application in industry is currently limited by low catalytic activity and product selectivity. Thus, a better understanding of the catalytic reactions as well as a strategy for the catalyst design can bring solutions for a complete and selective conversion into desired products. In this perspective, we review the status and challenges of electrocatalytic oxidation and hydrogenation of furanic compounds, including thermodynamics, voltammetric studies, and bulk electrolysis with important reaction parameters (i.e., catalyst, electrolyte, temperature, etc.) and reaction mechanisms. In addition, we introduce methods of energy-efficient electrocatalytic furanic synthesis by combining yields of anodic and cathodic reactions in a paired reactor or a reactor powered by a renewable energy source (i.e., solar energy). Current challenges and future opportunities are also discussed, aiming at industrial applications.

The reactivity and physicochemical properties of lignins are partly governed by their molar mass distribution. The development of reliable standard methods for determination of the molar mass distribution is not only relevant for designing technical lignins for specific applications, but also for monitoring and elucidating delignification and pulping processes. Size-exclusion chromatography (SEC) offers many advantages, such as wide availability, short analysis time, low sample demand, and determination of molar mass distribution over a wide range. A collaborative study has been undertaken within the “Eurolignin” European thematic network to standardise SEC analysis of technical lignins. The high-molar-mass fraction of polydisperse lignins was shown to be the main source of intra- and interlaboratory variations, depending on the gel type, elution solvent, detection mode, and calculation strategy. The reliability of two widespread systems have been tested: one based on alkali and a hydrophilic gel (e.g., TSK Toyopearl gel) and the other based on THF as solvent and polystyrene-based gels (e.g., Styragel). A set of practical recommendations has been deduced.