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The selective oxidation of 5‐(Hydroxymethyl)furfural (HMF) to 2,5‐Furandicarboxylic acid (FDCA) is highly attractive for the production of renewable monomers as substitute for fossil‐based monomers. To achieve a sustainable synthesis, we report on advances for a base‐free approach, reducing waste from the process, using air as oxidant and heterogeneous catalysts. Various Carbon‐based supports, which can be bio‐sourced and cost‐efficient, for Pt particles were investigated as they allow for an easy reuse and at the end‐of‐life Pt can be recycled to enable a closed cycle. Commercially available supports with varying properties, which might replace the base, were studied with Pt particles of similar size and loading. Significant differences in the catalytic activity were observed, which were correlated with the O‐functionalities and graphitization degree of the supports derived from Raman spectroscopy, temperature‐programmed desorption, and X‐ray photoelectron spectroscopy. An activated carbon (Norit ROX) rich in quinone/pyrone‐type groups and a carbon black‐based catalyst with graphene‐layers pushed the efficiency with enhanced FDCA‐yields enabling the complete substitution of the homogeneous base. This allows to circumvent the base in this process which together with high selectivity, air as oxidant, a reusable catalyst, and the use of bio‐based feedstock contributes to the sustainability of the production of renewable monomers. [ABSTRACT FROM AUTHOR]

Metal‐free catalytic systems (MFCS) have emerged as sustainable and cost‐efficient heterogeneous catalysts, particularly in the case of carbonaceous materials with oxygen, nitrogen, boron, sulfur or phosphorus functionalities. This contribution aims to provide a general overview of the recent advances on the design of such materials, with emphasis on those derived from biomass waste and on the relationship between their structure and their activity. The opportunities of using MFCS in different areas of catalysis, including thermo‐, electro‐, and photo‐catalysis, will be addressed for applications towards the upgrading of renewable feedstocks. This analysis will describe sustainable approaches not only with respect to the nature of catalyst but also for the employment of non‐toxic and sustainable precursors, and for the efficiency of the synthetic protocol and its carbon footprint. [ABSTRACT FROM AUTHOR]

The reduction of esters and aldehydes to alcohols is an important reaction in the chemical industry to produce a wide range of bulk and fine chemicals. Herein, the unexpected behavior of three state‐of‐the‐art, commercially available Ru‐catalysts for the hydrogenation of these feedstocks is reported. For ester and aldehydes containing a C=C bond, it was possible to carry out the selective hydrogenation of the ester or aldehyde functionality while keeping the C=C double‐bond essentially untouched. Furthermore, it is demonstrated that these substrates can be reduced under very mild reaction conditions (as low as 40 °C and 5 bar of H2) and that anisole, a solvent with a high sustainability rank, is suitable for these catalytic hydrogenations. [ABSTRACT FROM AUTHOR]