The production of diesel from vegetable oil calls for an efficient solid catalyst to make the process fully ecologically friendly. Here we describe the preparation of such a catalyst from common, inexpensive sugars. This high-performance catalyst, which consists of stable sulphonated amorphous carbon, is recyclable and its activity markedly exceeds that of other solid acid catalysts tested for ‘biodiesel’ production.
Green synthesis of 2,5-furandicarboxylic acid, one of the most important chemical building blocks from biomass, viaoxidation of 5-hydroxymethylfurfural has been demonstrated using hydrotalcite-supported gold nanoparticle catalyst in water at 368 K under atmospheric oxygen pressure without addition of homogeneous base.
5-Hydroxymethylfurfural (HMF), one of the most important intermediates derived from biomass, was directly produced from monosaccharides (fructose and glucose) and disaccharides (sucrose and cellobiose) by a simple one-pot reaction including hydrolysis, isomerization and dehydration using solid acid and base catalysts under mild conditions.
This review is intended to introduce recent progress in the characterization, synthesis and catalysis of hydrotalcite (HT) and HT-related materials. NMR, in situ neutron diffraction and TG–DTA techniques have been used to determine the local structure and structural changes of HT. Various synthetic methods of controlling the morphology of HT are introduced together with the crystal formation mechanism. The preparation methods of magnetic HTs are also included. The HT acts as a heterogeneous base catalyst for efficient transformations of organic compounds such as the synthesis of glycerol carbonate, transesterification of oils (biodiesel production) and carbon–carbon bond formations. The HT has also been used as a support for immobilizing various metal species (Ru, Pd, Ag, Au, Pt, Cu, V, Mn etc.), which enables highly selective organic reactions such as dehydrogenation of alcohols and deoxygenation of epoxides. Cooperative actions between basic sites of the HT surface and supported metal species are introduced. It is also shown that the HT can work together with other solid acids and metal catalysts to promote sequential reactions in a one-pot manner, which gives us a very important methodology for environmentally-benign synthesis of value-added chemicals, especially from biomass-derived compounds.