Transforming part of the feedstock base of the chemical industry from fossil feedstocks to biomass, as expected by many researchers and companies, requires fundamental changes in the technologies for processing. While fossil feedstocks are non-polar and processed at high temperatures in the gas phase, most biomass derived feedstocks are polar molecules, which are present in aqueous solution and are typically processed at relatively low temperatures in defunctionalization reactions. Yet, most approaches rely on the conventional wisdom of using catalysts developed for fossil feed processing where the conditions almost always exclude the use of polymeric catalysts. However, for the conditions of biomass processing, adapted polymeric catalysts could be ideally suited. This defines the goals of the proposed research program: known and newly designed polymeric catalysts will be explored with respect to their potential in biomass conversion reactions, which could lead to a new paradigm in catalytic biofeedstock processing. In order to achieve this objective, it will be attempted to produce four selected, exemplary classes of polymers in porous form with adjustable porosity. The porous polymer types will then be post-treated with different methods to introduce catalytic functionality (acid/base and redox functionality). The target processes in biomass conversion are prototypical examples which are representative for whole classes of reactions. These include the depolymerisation of the major components of lignocellulose (cellulose, hemicellulose and lignin) and the targeted synthesis of selected platform molecules starting from glucose as the depolymerisation product of cellulose. Successful completion would provide more efficient access to many novel value chains and establish a novel class of catalytic materials.