Muconic acid (MA) is a high value-added dicarboxylic acid with conjugated double bonds, presenting three isomeric forms, i.e., cis,cis-MA, cis,trans-MA and trans,trans-MA. Its production is garnering increased interest owing to its potential as a starting material for the synthesis of value-added products as well as by being a versatile monomer for the production of specialty polymers. This review presents a systematic overview of production and synthesis routes to MA isomers as well as the routes for its final valorization. The production of MA through chemical pathways and the progress developed in the biotechnological pathways will be discussed. Traditional and new processes for achieving successful isomerization into the value-added trans,trans form of MA are also discussed and compared, with their constraints and possible solutions. The valorization of the three different isomers of MA into value-added chemicals such as adipic or terephthalic acids and MA polymers are summarized. Finally, the review concludes with a thorough summary, a practical insights section and an outlook. This work thus offers new perspectives and guidelines to tackle the challenges in MA chemistry, especially when aiming to combine an efficient biotechnological production of MA with its valorization.

Using periodic density functional theory calculations combined with four dispersion-correction schemes, we have investigated the adsorption of phenol, toluene and water for various cation-exchanged faujasite zeolites. In the context of purifying the biofuels derived from the catalytic cracking of lignocellulosic bio-oils in a fluid catalytic cracking (FCC) unit, our aim was to find a suitable material with a higher affinity for phenol versus toluene and water, which are also present in the biofuel charge. In order to identify the most promising adsorbent materials, we have undertaken a full screening of monovalent cations which can be incorporated into the faujasite-type zeolite (FAU). We have evidenced that phenol can be adsorbed in two modes: O-interaction (where phenol is adsorbed via its oxygen) and π-interaction (where phenol is adsorbed via its aromatic ring). The screening of the interaction energies of the different exchanged zeolites showed that over HFAU the phenol is selectively adsorbed via O-interaction, contrary to what is observed over alkali and transition metal exchanged zeolites where the π-interaction dominates for the adsorption of phenol, leading to weaker interaction with the zeolite compared to toluene. On the Lewis modeled acid sites, namely the defect Lewis acid site (D-LAS) and the extraframework Lewis acid site (EX-LAS), the two interaction modes of phenol show almost equivalent interaction energies. In terms of selectivity, HFAU is the most selective to phenol adsorption towards O-interaction even in the presence of toluene and H₂O molecules. Both adsorption modes of phenol present a higher interaction energy than those of toluene and H₂O once adsorbed over an EX-LAS. The alkali and metallic cations have a high affinity for toluene molecules, which prohibit their use for the biofuel purification process.