Paraskevopoulou, PatrinaPatrinaParaskevopoulouGurikov, PavelPavelGurikovRaptopoulos, GrigoriosGrigoriosRaptopoulosChriti, DespoinaDespoinaChritiPapastergiou, MariaMariaPapastergiouKypritidou, ZachareniaZachareniaKypritidouSkounakis, VassilisVassilisSkounakisArgyraki, AriadneAriadneArgyraki2019-06-192019-06-192018-11-01Polyhedron (154): 209-216 (2018-11-01)http://hdl.handle.net/11420/2804We report the synthesis of W-doped biopolymer aerogels with potential applications to catalysis. The biopolymers were based on alginate, a cost-efficient natural material, and were prepared in environmentally friendly water/ethanol solutions. Gelation of alginate was induced by crosslinking with Ca2+. The resulting wet-gels were impregnated with an ethanolic solution of the ditungsten complex [W2(μ-OEt)2(OEt)2(EtOH)2Cl4] ({W = W}8+) and were dried with supercritical fluid (SCF) CO2 to yield W-doped alginate aerogels containing 10% w/w tungsten. Dry materials were characterized with FTIR, SEM/EDS, TGA, N2 porosimetry and He pycnometry. The bulk densities were low (<0.1 g cm−3), porosities were high (96% v/v), as well as the BET surface areas (380 m2/g). Pyrolysis of those aerogels at 800 °C under Ar yielded carbon along with a mixture of calcium tungstates, i.e., CaWO4 and Ca3WO6 (weight ratio: 70:30), while pyrolysis under O2 yielded the same tungstates, but with a different weight ratio (10:90). This can be a new process for Ca3WO6, which, due to its ordered double perovskite structure, is ideal for doping with metal ions, at relatively low temperature (800 °C versus >1000 °C in the literature).en0277-53872018209216Journal Article10.1016/j.poly.2018.07.051Other